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1. Masking noise will mask the contralateral ear This is done to de 41 6 ABR How to use 13 39 ABR lt r Ht Levels select 1 to 5 O 90 dB nHL WF 80 dB nHL WR 70 dB nHL WR 60 dB nHL WF 50 dB nHL WR 40 dB nHL O 30 dB nHL 20 dB nHL 10 dB nHL 85 dB nHL 75 dB nHL 65 dB nHL 55 dB nHL 45 dB nHL 35 dB nHL 25 dB nHL 15 dB nHL o 00 0 0000 0 5 dB nHL 13 41 ABR HD The initial stimulus level will be higher than 70 dB nHL Do you want to continue Yes 42 _No synchronize the stimulus related neural activity on the auditory pathway of the non tested ear which might be stimulated by cross hea ring It is recommended to always use this option especially in cases of asymmetrical hearing loss The masking level 1s controlled by the device and depends on the stimulus level and the electro acoustical transducer used Select Auto Proceed Auto Proceed will proceed the measurement at the next stimulus level when significance is reached for the current measurement Select Auto Stop Auto Stop will abort the test sequence 1f no significant response could be recorded for two consecutive stimulus levels Select stimulus levels At the level selection screen 1 to 5 levels can be selected Measure ment will be started at the highest stimulus level ABR amplitude decreases and latency increases with decreasing sti mulus level In normal hearing subjects wav
2. Please Note This test was initially designed for adults but it 1s also very likely to be used by school kids in grade 1 being able to read VCVs 33 5 SUN How to use In the following the use of the SUN test is described in detail Settings Screening level oo E gt Press SUN in the main menu to start measuring with SUN gt Select the ear you want to test all Bin binaural right ear E left ear gt After having pressed A in the footer select the hearing level you want to measure Press E or gt to change the current dB hearing level The currently selected level can be seen in between ses and The overall level is between 50 and 70 dB HL Measurement Select one ear or both ears to start the measurement 34 gt Different vev options are visualized A voice will pronounce one of them aCla NM 2 3 O O aDa gt The tested person shall select the heard pronunciation and press the accord ing button gt Going on with the measurement the signal to noise ratio will decrease aD 413 gt After 12 pronunciations the test ends automatically and the results are shown SUN test results SUN scores the number of correctly identified stimuli It determines whether hearing ability 1s within of below the normal range e The normal range is shown as a green signal light and lies between 9 and 12 out of 12 heard stimuli
3. BROWN A M HARRIS F P amp BEVERIDGE H A 1996 Two sources of acoustic distortion products from the human cochlea J Acoust Soc Am 100 3260 7 BROWN A M WILLIAMS D M amp GASKILL S A 1993 The effect of aspirin on cochlear mechanical tuning J Acoust Soc Am 93 3298 307 BROWNELL W E BADER C R BERTRAND D amp DE RIBAUPIERRE Y 1985 Evoked mechanical responses of isolated cochlear outer hair cells Science 227 194 6 BURNS E M KEEFE D H amp LING R 1998 Energy reflectance in the ear canal can exceed unity near spontaneous otoacoustic emission frequencies J Acoust Soc Am 103 462 74 DALLOS P 1992 The active cochlea J Neurosci 12 4575 85 DAVIS H 1983 An active process in cochlear mechanics Hear Res 9 79 90 DORN P A KONRAD MARTIN D NEELY S T KEEFE D H CYR E amp GORGA M P 2001 Distortion product otoacoustic emission input output func tions in normal hearing and hearing impaired human ears The Journal of the Acoustical Society of America 110 3119 3131 DOYLE K J FUJIKAWA S ROGERS P amp NEWMAN E 1998 Comparison of newborn hearing screening by transient otoacoustic emissions and auditory brainstem response using ALGO 2 Int J Pediatr Otorhinolaryngol 43 207 11 FAUSTI S A LARSON V D NOFFSINGER D WILSON R H PHILLIPS D S amp FOWLER C G 1994 High frequency audiometric monitoring strategies for early detection of ot
4. e Ifthe hearing ability is slightly below the normal range the score is shown as a yel low light For this result the tested person must identify 7 to 8 out of 12 stimuli e Below the hearing ability the score is shown as a red light for which the tested person heard only 0 6 out of 12 stimuli gt Click on ViewResults jn the main menu in order to display the test results of the selected patient gt Now press A Y 1 to see the details of the test result P is the result for a tested right ear for the left and for binaural 35 5 SUN How to use 20 57 SUN om Test Level 60 dB HL gt This result for example displays a SUN test with 60 dB on both ears The tested person heard 9 out of 12 stimuli correctly The green signal light Result 9 12 aie stands for a normal hearing ability of the tested person E e 36 6 ABR How to use Auditory brainstem responses ABRs recorded from electrodes placed on the scalp represent the far field of potentials generated by the fiber tracts and nuclei of the ascending auditory pathway between the cochlea and the brainstem The ABR latency epoch consists of up to seven prominent wave peaks which appear within the first 10 ms Commonly ABRs are elici ted by transient stimuli click tone burst chirp ABRs represent the sum of synchronized neural activity of the ascending auditory pathway Wave I and II stem from auditory nerve wav
5. PATH Z MEDICAL SOLUTIONS PATH medical GmbH Senti and Sentiero HOW TO MANUAL HINTS AND CLINICAL APPLICATION METHODS AND SCIENTIFIC BACKGROUND Revision 1 Valid for Senti and Sentiero firmware version 1 3 and following April 2011 Revision History Rev Date Author Approved Released Description Changes tt mm yy date amp sign date amp sign Draft 1 17 05 11 TJ SK Initial Rev 2 7 12 11 TJ VS osw ABR added Copyright remains with the authors Please refer to the literature reference list Reprint even partially only allowed with written notice from the authors All mentioned items products brands and trademarks are registered owned by the mentioned companies This How To Manual is subject to change without notice Errors and omissions excepted Disclaimer This How To Manual is provided as 1s PATH medical has taken care that the contents and descriptions are correct The content was gathered and proof read under scientific contribution of professionals and long term experts in the field Selected literature 1s provided to enable the reader to read more on the scientific background of the methods implemented in Senti and Sentiero PATH medical cannot take any liability arising from mis interpretation or mis application of this How To Manual and the provided references therein Contact PATH medical GmbH Landsberger Stra e 63 82110 Germering Germany Tel
6. blue c Mean and standard deviation of estimated DPOAE thresholds DPOAE audio grams of left blue and right ears red obtained in 100 newborns d DPOAE audiograms can be applied in newborns to reveal a temporary sound con ductive hearing loss or to detect a persisting cochlear hearing loss In follw up dia gnostics DPOAE audiograms can serve as an advanced tool for bridging the gap between screening and audiological testing DPOAE audiograms are useful in pediatric audiology since they provide fre quency specific information about the hearing loss in a couple of minutes Thus they have an advantage over TEOAESs or click evoked ABRs because they can not quantitatively assess cochlear hearing thresholds at distinct test frequencies and ASSRs because their measuring time is extremely long Three case examples shall demonstrate the efficacy of DPOAE audiograms in pediatric audiology Fig 8 6 a b c In a 6 years old boy pure tone audiogram and DPOAE audiogram exhibited a close correspondence Fig 8 6 a However in the younger children there was a high discrepancy between the behavioural free field audiograms and the DPOAE audiograms The free field audiogram of a 5 month old girl Fehler Referenz nicht gefunden b indicated a hearing loss of 50 dB HL in the entire frequency range However the DPOAE audiogram revealed a hearing loss only in the mid and low frequency region Fehler Referenz nicht gefunden c Relation between D
7. EN E E Cay tone A A A gt If the tone was heard press the happy animal key botton right gt If the tone was not heard press the unhappy animal botton left AER Select the next wn Click on the beig animal to elicit a animal tone gt If the tone was heard hit the happy animal key if not hit the unhappy animal with the scarf ame mac 9 m SA aa Click on the big animal No tone will N animal a be heard In the Instruction phase the third animal is muted to test the manual input of the tested person Se a i ye lect the next animal Additional instruction phases can be manually triggered by pressing Re mst in settings a in the screen footer MAGIC How to use Measurement Phase After the successful completion of the instruction phase the measurement phase with adaptive level presentations starts automatically SM b R 3B MAGIC mute 9 Ea En A N gt The child shall now select the next animal from the rack smem gt The child shall hit the happy animal if the tone was heard or hit the sad Ca animal if the tone was not heard gt If the child seems indecisive ask him her to hit the big animal again to repeat S n the sound gt Continue selecting the next animals until the automatic end of the test A mute tone will be presented randmomly with every 4 to 6 animal to verify the correctness of the child s answers and to keep up the children s motivatio
8. In this baby Eustachian tube dysfunction could have been the cause for the hearing loss within the first days of life where middle ear stiffness is increased and therefore low frequencies are affected In another newborn with a refer ATEOAE screening response the DPOAE audio gram indicated a hearing loss of more than 50 dB at 1 5 2 3 and 6 kHz arrows and a 40 dB hearing loss at 4 kHz The second measurement 12 days later revealed normal hearing function In this baby both a low and a high frequency sound conductive hearing loss might have been present where middle ear stiffness 1s increased due to Eustachian tube dysfunction and thus low frequencies are affected and middle ear mass is increased due to amniotic fluid and thus high fre quencies are affected 73 9 OAE Description of Methods Fig 9 6 d shows mean and standard deviation of estimated DPOAE thresholds measured in 100 left and 100 right ears from 100 newborns at neonatal care unit Mean age was 2 5 days There was no significant difference between left and right ears Standard deviation is partly due to different sound conductive conditions during the early postnatal period Results indicate that DPOAE threshold measure ments can be done under hearing screening conditions 8 KHz Fig 9 6 Pure tone audiograms black symbols and DPOAE audiograms in 3 children 6 years old right ear a 5 months old right ear b 3 months old right red and left ear
9. 1978 Stimulated acoustic emissions from within the human auditory system J Acoust Soc Am 64 1386 91 KEMP D T BRAY P ALEXANDER L amp BROWN A M 1986 Acoustic emission cochleography practical aspects Scand Audiol Suppl 25 71 95 KEMP D T amp RYAN S 1991 Otoacoustic emission tests in neonatal screening programmes Acta Otolaryngol Suppl 482 73 84 KEMP D T RYAN S amp BRAY P 1990a A guide to the effective use of otoacoustic emissions Ear Hear 11 93 105 References KEMP D T RYAN S amp BRAY P 1990b Otoacoustic emission analysis and interpretation for clinical purposes In GRANDORI F CIAFRONE G amp KEMP D eds Cochlear mechanisms and otoacoustic emissions Karger KOPELMAN J BUDNICK A S SESSIONS R B KRAMER M B amp WONG G Y 1988 Ototoxicity of high dose cisplatin by bolus administration in patients with advanced cancers and normal hearing Laryngoscope 98 858 64 KUMMER P JANSSEN T amp ARNOLD W 1998 The level and growth beha vior of the 2 f1 f2 distortion product otoacoustic emission and its relationship to auditory sensitivity in normal hearing and cochlear hearing loss Journal of the Acoustical Society of America 103 3431 3444 KUMMER P JANSSEN T HULIN P amp ARNOLD W 2000 Optimal L 1 L 2 primary tone level separation remains independent of test frequency in humans Hear Res 146 47 56 LASKY R E 1998a Distortion p
10. A more relevant measure is the intersection point between the extrapolated DPOAE I O function and the prima ry tone level axis at which the response s sound pressure is zero and hence at which OHCs are inactive Boege and Janssen 2002 Gorga et al 2003 A linear dependency between the DPOAE sound pressure and the primary tone sound pres sure level is present Boege and Janssen 2002 when using the scissor paradigm for eliciting DPOAEs Kummer et al 2000 Because of the linear dependency DPOAE data can be easily fitted by linear regression analysis in a semi logarith mic plot where the intersection point of the regression line with the L2 prima ry tone level axis at pdp 0 Pa can thus serve as an estimate of the DPOAE thres hold The estimated DPOAE threshold Ldpth is independent of noise and seems to be more closely related to behavioural threshold than the DPOAE detection thres hold Boege and Janssen 2002 Gorga et al 2003 When converting DPOAE sound pressure level SPL to hearing level HL the estimated DPOAE thresholds can be plotted in an audiogram form DPOAE au diogram DPOAE audiograms can be applied in babies with a refer result in newborn hearing screening to reveal a transitory sound conductive hearing loss due to Eustachian tube dysfunction and or amniotic fluid in the tympanic cavity or to confirm a persisting cochlear hearing loss in follow up diagnostics Test time for establishing a DPOAE audiogram takes
11. HARRIS F P PROBST R amp WENGER R 1991 Repeatability of transiently evoked otoacoustic emissions in normally hearing humans Audiology 30 135 41 HATZOPOULOS S PETRUCELLI J MORLET T amp MARTINI A 2003 TEOAE recording protocols revised data from adult subjects Int J Audiol 42 339 47 HE N amp SCHMIEDT R A 1997 Fine structure of the 2 f1 f2 acoustic distor tion products effects of primary level and frequency ratios J Acoust Soc Am 101 3554 65 HE N J amp SCHMIEDT R A 1993 Fine structure of the 2f1 f2 acoustic distor tion product changes with primary level J Acoust Soc Am 94 2659 69 HE N J amp SCHMIEDT R A 1996 Effects of aging on the fine structure of the 2f1 f2 acoustic distortion product J Acoust Soc Am 99 1002 15 HEITMANN J WALDMANN B SCHNITZLER H U PLINKERT P K amp ZENNER H P 1998 Suppression of distortion product otoacoustic emissions DPOAE near 2f sub 1 f lsub 2 removes DP gram fine structure Evidence for a secondary generator The Journal of the Acoustical Society of America 103 1527 1531 JANSSEN T BOEGE P MIKUSCH BUCHBERG J amp RACZEK J 2005a Investigation of potential effects of cellular phones on human auditory function by means of distortion product otoacoustic emissions The Journal of the Acoustical Society of America 117 1241 1247 81 11 References 82 JANSSEN T BOEGE P OESTREICHER E amp ARN
12. a couple of minutes DPOAE audio grams are an alternative method to behavioural audiometry or frequency specific evoked response audiometry tone burst auditory brain stem responses ABRs auditory steady state responses ASSRs in case of mild and moderate hearing Clinical applications of TEOAEs DPOAEs loss In contrast to TEOAE common DPOAE elicited at high primary tone levels and click evoked ABR which only qualitatively describe the hearing loss DPOAE audiograms are able to quantitatively assess the hearing loss at distinct frequencies This is an essential advantage over tone burst ABR or ASSR Predic ting hearing loss at five frequencies by tone burst ABR or ASSR takes more than half an hour Thus DPOAE audiograms can serve as an advanced tool for bridging the gap between screening and audiological testing in pediatric audio logy The objective of hearing screening in childhood is to identify hearing impair ment which are not obvious or apparent and will cause significant disability or handicap for the child concerned Late identification may compound problems in communication language acquisition and affect other areas of development Con trary to newborn hearing screening preschool hearing screening tests should provide more frequency specific and quantitative information on the hearing loss Extrapolated DPOAE I O functions provide a frequency specific and quantitative assessment of the hearing loss The DPOAE growth ra
13. conduction pure tone thresholds Stimulus settings for air conduction are the same as those for PTA 4 advanced Maximum stimulus levels for bone conduction are as follows 35 dB HL for 0 25 kHz 50 dB HL for 0 5 kHz 60 dB HL for 2 kHz and 3 kHz 50 dB HL for 4 kHz 40 dB HL for 6 kHz and 35 dB HL for 8 kHz Air conduction stimuli can be delivered via headphones or insert sound probes However when using insert sound probes maximum stimulus level is by 10 dB lower with the exception at 0 25 kHz Please note As PTA 1s a psycho acoustical test method the ability willingness and concentra tion of the subject to co operate are essential Be aware that there can be a large discrepancy between PTA and real threshold in infants and young children In these cases it is advised to perform DPOAE Threshold In the following the use of the PTA 4 PTA 4 advanced and PTA 3 is described in detail Measuring with PTA a e ges oh gt The currently selected sound level is shown in between the i y arrows k 3k dk 6k 8kH2 Step 1 gt Select the stimulus level with the arrows Step 2 gt Select the frequency level with the EE EA arrows PTA How to use Step 3 AC Right ED 1022 500 ik 2k 3k 4k 6k kHz gt Press to elicit a stimulus E jii Note The tone will be played as long as Dis pressed 3 turns hen the tone is elicited The patient response button GD turns light green lt a when the p
14. do not allow OAE measurements at very low stimulus levels Especially below 0 5 kHz reliable OAE measurements are not possible even at high stimulus levels Second because of the limited fre quency range of the sound probe s electro acoustic transducers high frequency OAE measurements are difficult without using specialized devices Third stan ding waves in the outer ear canal make a defined stimulus setting difficult to obtain Fourth beside the main DPOAE source at f2 a secondary DPOAE source is present at the 2f1 f2 place which interacts with the main source constructively or destructively at the f2 place Whitehead et al 1992 Brown et al 1996 Shera and Guinan 1999 Therefore the DPOAE does not exactly reflect OHC function at the f2 place When all these factors are considered it is easy to see how OAE measures can be misinterpreted 9 2 Clinical applications of TEOAEs DPOAEs 30 years after the discovery of OAEs OAE measurements are a standard part of the audiometric diagnostic test battery OAEs are a means of acquiring non inva 59 9 OAE Description of Methods 60 sive information about disorders of an essential element of sound processing 1 e the cochlear amplifier CA and hence allow assessment of loss of sensitivity compression and frequency selectivity of the hearing organ Like tympanomettry which examines the status of the middle ear OAEs are a fast and easy to handle method for examining cochl
15. for case examples see How to Manual Part II Due to standing waves in the outer ear canal stimulus and response can not always be reliably be determined and thus DPOAE thresholds do not always match pure tone thresholds This is true especially for high ear canal volumes If this is the case a discrepancy between DPOAE thresholds and PTA thresholds mainly occurs in the mid frequency region around 3 kHz and at the higher test frequencies gt 6 kHz Very important if there is no OAE response the following pathologies are possi ble sound conductive hearing loss cochlear hearing disorder of at least 30 dB hearing loss TEOAE or at least 50 dB hearing loss DPOAE Therefore tympa nometry auditory brain stem responses and auditory steady state responses have to be performed to assess the type and the degree of the hearing loss In the following the use of the different OAE tests is described in detail OAE ai E 4 gt Press a TEE to start TEOAE menu sel a DPOEA Threshold a LE _ OAE How to use gt Press 7 to select the frequencies you want to test a ial gt To start the measurement please choose between right and left ear aa gt Acalibration of the ear probe will first be performed before the measurement Incomplete Starts gt Ifthe probe is not placed properly in the ear canal the message incomplete will appear on the display In this case please correct the posit
16. form of a tabletop unit Sentiero provides audiometer facilities in the form of a handheld device meeting all demands of a basic diagnostic audiometer of class 3 according to DIN IEC 60645 1 In screening PTA the test results show whether the hearing threshold levels are better equal to or worse than the screening level used The subject passes the screening test according to predefined criteria e g a pass occurs if all tones are heard in each ear Screening at certain selected levels and frequencies is faster than measuring hearing threshold levels In order to perform PTA screening with Sen tiero test frequencies and predefined levels can be selected by the user Intended use of PTA is to determine pure tone thresholds in preschool and school children Also PTA can be used in clinics bed side use ambulances outpatient clinics and occupational medicine Three different modes are available depending on the device s license key PTA4 for assessing air conduction pure tone thresholds at frequencies 0 25 0 5 1 2 3 4 and 6 kHz Stimulus level can be set from 0 to 70 dB HL PTA 4 advanced 15 3 PTA How to use 16 for assessing air conduction pure tone thresholds at PTA 4 frequencies 8 kHz Stimulus level can be set from 10 to 100 dB HL for 0 5 1 2 3 and 4 kHz from 10 to 90 dB HL for 6 kHz from 10 to 80 dB HL for 8 kHz from 10 to 70 dB HL for 0 25 kHz PTA 3 for assessing air conduction and bone
17. low level sound emissions that occur with sound pressure levels from a maximum amounting to about 20 dB SPL down to the limiting noise floor level Therefore the recording of OAEs requires the use of a highly sensitive low noise microphone For DPOAE recording separate loudspeakers are commonly used for each primary tone in order to exclude technically generated distortion com ponents Both the microphone and the loudspeakers of the ear probe need to be miniaturized so that the ear probe is small enough to be placed inside the ear canal Fehler Referenz nicht gefunden A tight fit of the probe 1s essential for OAE recording If there is leakage between the ear tip and ear canal low frequency sound components cannot be recorded properly Furthermore the closure of the ear canal by the ear tip excludes external sounds In addition it is essential to make sure that the ear canal is clean and that the ear probe ports are not blocked with ear canal wax For clinical practice it is important that ear probes are desi gned to offer easy access for cleaning ports or replacing clogged ear tips To achieve low noise floor levels OAE measurements are conducted in a sound attenuating booth or any other quiet environment For bedside use portable mea suring devices are used Automated measuring and evaluation procedures guaran tee test consistency and simplify the interpretation of OAE recordings Fourier transform FFT computations from the time domain
18. reported a change in IPL others claim that there is no delay in neural transmission time with ageing Also no significant corre lation was observed between the score of speech discrimination tests and IPL Sensitivity of ABRs is quite low below 1000 Hz due to poor synchrony of neural aktivity in the apical region of the cochlea Click evoked ABR does not allow direct frequency specific assessment of hearing loss Click evoked ABRs exhibit nearly normal patterns in patients with low and or mid frequency hearing loss Low frequency stimulation at high stimulus levels will also stimulate basal sensory cells Thus assessment of low frequency functionality 1s only possible at low stimulus levels For getting more frequency specific information DPOAE at a 37 6 ABR How to use hearing loss up to 50 dB or tone pip and chirp evoked ABR have to be used However when applying low frequency stimulation at high stimulus levels the basal region of the cochlea is also stimulated Thus frequency specificity of ABRs is restricted Compared to ABRs audi tory steady state responses ASSRs available in 2012 provide better frequency specificity In patients with hearing loss wave I may be missing In these patients determination of IPL is not possible and thus neural disorders can not reliably be assessed Correct placement of elec trodes is crucial in order to yield optimal ABR patterns Due to the fact that electro magnetic fields have impac
19. selectivity of the hearing organ Liberman and Dodds 1984 OAEs as a by product of cochlear non linear sound amplification then appear with reduced amplitude or disappear Mills and Rubel 1994 Spontaneous OAEs SOAEs appear without any sound stimulation at a few fre quencies in a healthy cochlea and seem to be a direct consequence of the cellular force generation of outer hair cells OHCs Zwicker and Schloth 1984 Burns et al 1998 Julicher et al 2003 SOAEs do not appear in each normally hearing subject and are present in about a half of the normally hearing population with a distinctly higher prevalence in women than in men Bilger et al 1990 Penner et al 1993 Penner and Zhang 1997 SOAEs are therefore not suited for audiologi cal diagnostics Evoked OAEs are generated by external sounds either by transient clicks and tone bursts or stationary stimuli tones Transiently evoked OAEs TEOAES elicited by clicks or tone bursts represent the sum of the pulse responses of OHCs 57 9 OAE Description of Methods 58 along the cochlea TEOAEs already disappear at mild hearing losses and are there fore a suitable tool for newborn hearing screening which 1s a selection procedure for deciding whether further diagnostics are advised or not Robinette and Glattke 2002 Distortion product OAEs DPOAEs represent cubic distortions of OHCs when stimulated simultaneously by two tones fl lower frequency and f2 hi
20. simplified estimation where less than three valid responses are present and the lowest primary tone level 15 dB is the estimate arrow symbol means no DPOAE are measurable and thus the hearing loss 1s higher than 50 dB HL Fig 9 4 Otoacoustic emissions TEOAE and DPOAE are widely regarded as being suit able for screening in newborns and infants as they are not present in the case of outer hair cell dysfunction e g Kemp and Ryan 1991 Gorga et al 2000b Norton et al 2000b Norton et al 2000a The premise for this approach is that inner ear hearing loss always includes OHC damage or malfunction However conductive losses also cause refer results under screening conditions mainly due to the attenuation of an existing OAE signal 71 9 OAE Description of Methods 12 f 1 kHz f 2 kHz fo 3 kHz f 6 kHz O o oat SNR E o lt 6 dB E L min 15 dB no extrapolation O DPOAE threshold 0 40 50 60 30 40 50 60 30 40 50 60 30 40 50 60 L dB SPL L dB SPL L dB SPL L dB SPL TJ DPOAE audiogram I a i 2 4 8 Zo 4 o 8 10 2 Do Z E 30 340 o 50 f kHz Fig 9 4 Schematic drawing of how to determine DPOAE thresholds and to estimate hearing loss at different test frequencies f2 DPOAE audiogram DPOAEs are plotted in double logarithmic L across L2 and semi logarithmic p across L2 scales Intersection of the lin ear regression line with L2 axis serves as a
21. the DPOAE component phase to the phase of the primary tones The phase statistics average normalized phase vectors of the signal received at the known DPOAE frequency Like the binomial statistics the vector sum can be scaled in probability terms pro viding defined and very high sensitivities A typical level of significance exceeds 99 per single frequency test 9 4 TEOAE DPOAE reproducibility 66 The inter individual variance of the TEOAE level is high standard deviation gt 10 dB Kemp et al 1986 Probst et al 1987 Bonfils and Uziel 1989 Smurzynski and Kim 1992 The intra individual variance of the DPOAE level is much smaller standard deviation lt 2 dB Johnsen and Elberling 1982b Johnsen and Elberling 1982a Harris et al 1991 Recently Janssen et al 2005a showed that repetitive DPOAE measurements with unchanged sound probe position exhibited an exponentially increasing standard deviation of DPOAE level with increasing SNR For example at a SNR of 10 dB the standard deviation amounts to 1 8 dB at a SNR of 20 dB to 0 7 dB and at a SNR of 40 dB to 0 1 dB This means that the higher the SNR the higher is the reliability of the DPOAE measurement This fin ding is important with respect to the evaluation of small DPOAE changes For cli nical practice however repetitive OAE measurements with changed sound TEOAE DPOAE reproducibility probe position are relevant For example the standard deviation when changin
22. the belly Do you hear the sound This animal does not make a sound You cannot hear any thing lower is selected automatically No interaction needed A muted tone is given The unheard animal with scarf is to be pressed Start the test If the child is not able to react in the right way repeat instruction phase using the Re Instr button in the settings menu In the following the course of actions and the corresponding settings for instruc tion Instruction Phase and measurement Measurement Phase is described in detail Also it is described how test results are displayed Test Results Instruction Phase in images The introduction phase starts automatically and makes the test person acquainted with the test procedure During the introduction phase the letter IP is displayed in the header A story told by the tester will motivate the child for the test and will explain the test procedure W gt Select one animal from the screen The order in which the different animals are selected is optional A Different animals represent different frequencies A n A a a 500 Hz 1000 Hz 2000 Hz 4000 Hz 9 N 4 250 Hz vv 3000 Hz 6000 Hz 8000 Hz 11 2 MAGIC How to use The introduction phase consists of three steps First step at stimulus level which should be heard easily Click on the big animal to elicit a ee S bR 4048 MAGIC
23. traced to a specific frequency component of the transient signal As the basilar membrane at basal sites moves faster than at more apical sites high frequency TEOAE components stem from basal cochlear sites whereas low frequency TEOAE components come from more apical ones Howe ver due to the fact that the stimulus and the high frequency TEOAE components superimpose and therefore have to be canceled during TEOAE recording TEOAEs fail to measure cochlear function above 4 kHz In contrast DPOAEs have the advantage of being capable of superior detection of a high frequency hea ring loss This 1s due to the fact that stimulus primary tones at f2 and fl and response 2f1 f2 do not superimpose However calibration errors due to standing waves in the outer ear canal can lead to misinterpretation of DPOAE results above 6 kHz The relation between OAE level and auditory threshold or rather the lack of it 1s strongly debated Earlier it was common to define confidence limits to deter mine the degree of certainty with which any measured response could be assigned to either normal or impaired hearing Gorga et al 1996 Gorga et al 2000a or to define a DPOAE detection threshold as the stimulus level at which the response equalled the noise present in the instrument Dorn et al 2001 However since the noise is of technical origin e g microphone noise the threshold evaluated in this way does not match the behavioural threshold
24. 2 14 ms Latencies ms IPL ms PMI 14 M2 T 28 T 60 6 1 60 50 64 50 40 A pl 40 30 30 30 40 50 60 10 90 click level dB nHL 4 Retrocochlear hearing loss Click evoked ABRs in a female patient with neural disorders at 80 dB nHL stimulus level ABR wave pattern 1s different compared to the normally hearing subject and the patients with cochlear or conductive hearing loss with respect to I V IPL I V ILP is prolonged 4 4 ms due to disturbed synchronisation of nerve fibers exceeding normal I V interval female mean 3 8 ms 0 2 ms standard deviation male mean 4 0 ms 0 2 ms standard deviation Stimu lus rate was set to 10 Hz horizontal electrode montage 48 ABR case examples Soon a0 m 0 2 4 6 8 10 12 14 16 ms Latencies ms IPL ms AMI 12 MAL 80 1 7 44 6 1 80 27 44 17 49 6 ABR How to use Part Il Description of Methods Description of the methods used in Senti and Sentiero is presented in the follo wing OAEs are higly sophisticated measuring procedures Therefore mechanism of OAE generation recording reproducibility stimulus parameter settings cali bration procedures and clinical applications are described in detail Especially the relationship between DPOAE thresholds and behavioral pure tone thresholds is discussed Addtionally case examples for using DPOAE audiograms in clinical practice are given A comprehensive list of references t
25. 49 89 800 76 502 Fax 49 89 800 76 503 http www pathme de Table of Contents 1 Overview 7 2 MAGIC How to use 9 3 PTA How to use 15 4 OAE How to use 21 5 SUN How to use 33 6 ABR How to use 37 6 1 Preparation of the patient to be tested 0 0 0 cece nce nen 39 6 2 Perform measurements ni ips 39 0 ABR CIE CX AIP ICS A AA AAA A 46 7 MAGIC Description of Methods 53 8 PTA Description of Methods 55 9 OAE Description of Methods 57 Daly Types Or DAS rbd ida 57 9 2 Clinical applications of TEOAEs DPOAES 0 0 000 ccc ccc ccc neces 59 233 TEOAE DPOAPE TeCOrGin a a des 64 9 4 TEOAE DPOAE reproducibility 0 000 n ence cence 66 9 5 TEOAE DPOAE stimulus setting 000 0 0 occ ccc nn 67 9 6 TEOAE DPOAE stimulus calibration 00 0000 n eens 69 9 7 Relation between DPOAEs and behavioural pure tone thresholds 70 10 SUN Description of Methods 77 11 References 79 Part How to use the methods provided by Senti and Sentiero Senti and Sentiero are portable hand held device designed for facilitating the assessment of hearing impairment in infants children and adults The purpose of the How to Manual is to get familiar with all the methods present on both devices especially the full featured Senti and Sentiero The devices are modular so sub sets of the methods are availabel This how to manual has two parts Part I describes how to use the different m
26. L L Primary tones f f f pS f 1 TEOAE p travelling wave due to waves due click to primary tones secondary DPOAE source primary as i tympanic DPOAE 7 eee oudspeaker membiane source g of overlap cochlea outer ear canal tympanic cavity Fig 9 1 Schematic drawing to show how TEOAEs and DPOAEs are evoked within the cochlea and subsequently measured in the outer ear canal The sound probe consists of either one loudspeaker for applying a click stimulus TEOAE or of two loudspeakers for applying two independently generated primary tones shown at top right with frequencies f and f and levels L and L and one microphone Mic for measuring the acoustic response signal TEOAEs represent OHC pulse responses along the basilar membrane Basal responses appear at the beginning and apical responses at the end of the TEOAE time function DPOAEs are generated within the region of overlap of the traveling waves of the two primary tones close to the f place A D Analog Digital Converter D A Digital Analog Con verter PC Personal Computer L sound pressure level p sound pressure f frequency t time 65 9 OAE Description of Methods There are several objective methods for separating the emission signal from the background noise and for automatically evaluating the validity of a recorded emission For TEOAEs mainly three signal evaluation approaches are used The first met
27. OLD W 2000 Tinnitus and 2f1 f2 distortion product otoacoustic emissions following salicylate overdose J Acoust Soc Am 107 1790 2 JANSSEN T GEHR D D KLEIN A amp MULLER J 2005b Distortion product otoacoustic emissions for hearing threshold estimation and differentiation between middle ear and cochlear disorders in neonates J Acoust Soc Am 117 2969 79 JANSSEN T KUMMER P amp ARNOLD W 1998 Growth behavior of the 2 fl f2 distortion product otoacoustic emission in tinnitus J Acoust Soc Am 103 3418 30 JANSSEN T NIEDERMEYER H P amp ARNOLD W 2006 Diagnostics of the cochlear amplifier by means of distortion product otoacoustic emissions ORL J Otorhinolaryngol Relat Spec 68 334 9 JOHNSEN N J amp ELBERLING C 1982a Evoked acoustic emissions from the human ear I Equipment and response parameters Scand Audiol 11 3 12 JOHNSEN N J amp ELBERLING C 1982b Evoked acoustic emissions from the human ear II Normative data in young adults and influence of posture Scand Audiol 11 69 77 JULICHER F CAMALET S PROST J amp DUKE T A J 2003 Active ampli fication by critical oscillations Jn GUMMER A ed Biophysics of the Coch lea from Molecule to Models New Jersey World Scientific KEEFE D H BULEN J C AREHART K H amp BURNS E M 1993 Ear canal impedance and reflection coefficient in human infants and adults J Acoust Soc Am 94 2617 38 KEMP D T
28. POAEs and behavioural pure tone thresholds shows the free field audiogram and the DPOAE audiograms of the left and the right ear The free field audiogram indicated a hearing loss of 40 dB HL In the left ear no DPOAEs were measurable indicating that the hearing loss must be higher than 50 dB arrows in Fehler Referenz nicht gefunden c In the right ear the DPOAE audiogram revealed normal hearing DPOAE audiograms may assess cochlear hearing loss more precisely than beha vioural tests especially in infants where the conditioned free field audiogram does not reflect the real threshold Moreover unilateral hearing loss can be detected DPOAE audiograms are an automated measuring procedure with simple handling and short measuring time No sedative 1s necessary in most cases It should be emphasized that DPOAEs only reflect outer hair cell functionality and therefore are not present at a hearing loss higher 50 dB HL However the incidence of a hearing loss higher than 50 dB is low Thus in most of the children DPOAE are measurable In cases where DPOAEs are not measurable ABRs or ASSRs have to be applied 75 1 0 SUN Description of Methods SUN is a novel self controlled speech in noise test designed for screening adults and older adults for hearing disability using a set of intervocalic consonants VCVs see Paglialonga A Tognola G Grandori F 2011 SUN test Speech Under standing in Noise a method for hearing disability scree
29. a L1 L2 setting described by L1 0 4L2 39 This scissor Lill setting L1 65 L2 65 L1 63 L2 60 L1 61 L2 55 L1 59 L2 50 L1 57 L2 45 L1 55 L2 40 L1 53 L2 35 L1 51 L2 30 L1 49 L2 25 L1 47 L2 20 was derived from findings on the influence of the Z1 Z2 setting on the DPOAE level Ldp Kummer et al 2000 It should be emphasized that it is not the L1 L2 setting but the scissor L1 L2 setting which yields compressive DPOAE growth reflecting non linear CA sound processing Fig 9 3 TEOAE DPOAE stimulus setting Fig 9 2 Scissor paradigm L1 0 4L2 39 for yielding best overlap of the primary tone travel ling waves 9 6 TEOAE DPOAE stimulus calibration Stimulus calibration is important to ensure proper data interpretation and compa rability There is a serious problem with stimulus calibration since due to stand ing waves in the ear canal the sound pressure level at the ear drum cannot be accurately set from measurements at the tip of the sound probe The most commonly used calibration method is the in the ear calibration based on the measurement of the sound pressure level at the ear probe microphone for con stant voltage at the loudspeaker Whitehead et al 1995b However the ear probe microphone is located in the outer ear canal while the relevant magnitude for the generation of OAEs is the actual sound pressure level at the eardrum Thus dependent on ear canal length and middle ear impedance there is a frequency d
30. able down to 10 dB nHL Wave V latency increases and wave V amplitude decreases with decreasing stimulus level Wave V latencies are within normal range 16 12 ABR e Ma 18 51 PTA Result o Wave V 500 50 rh part Audiogram 40 a ee ATEN EE A e latency ms 0 2 4 6 8 10 12 14 ms Latencies ms IPL ms EMI 1 7 MAL 50 62 50 50 A click level dB nHL 2 Conductive hearing loss Click evoked ABRs in a patient suffering from a conductive hearing loss at 80 70 60 50 and 40 dB nHL stimulus levels Wave V latency is increased being out of normal wave V latency range ABR threshold is reached at 50 dB dB nHL corresponding to the hearing loss at high frequencies Stimulus rate was set to 20 Hz vertical electrode montage 46 ABR case examples 17 38 ABR e EF 16 38 PTA Result gt Wave Y 5p0ny 80 eee Z DIT OASI Audiogram 70 latency m s 0 2 4 6 B 10 12 14 ms Latencies ms IPL ms I lll 14 MA 80 6 0 a0 E Tae y T 10 T 50 Ti 70 click level dB nHL 3 Cochlear hearing loss Click evoked ABRs in a patient suffering from a moderate high frequency cochlear hearing loss at 70 60 50 40 and 30 dB nHL stimulus levels In comparison to the normally hearing subject ABRs appear with lower amplitude and slightly increased wave V latency ABR threshold 1s reached at 30 dB nHL The prolongation of latency at low stimulus levels corres ponds to the propagation time of th
31. alternative means for revealing a temporary hearing loss in the early postnatal period caused by a tem porary sound conductive hearing loss due to amniotic fluid or Eustachian tube dysfunction When applying DPOAE audiograms before ABR screening time and Relation between DPOAEs and behavioural pure tone thresholds costs can be saved in those babies where DPOAEs are measurable and thus no additional ABR 1s needed newborn ATEOAE pass day 3 O day 86 newborn Il ATEOAE refer O day 1 O day 13 Fig 9 5 DPOAE audiograms in two newborns with temporary sound conducted hearing loss Newborn with a pass ATEOAE screening response exhibited a low frequency hear ing loss in the first measurement 3 days after birth In the second measurement 86 days after birth the DPOAE audiogram indicated normal hearing In newborn II with a refer ATEOAE screening response no DPOAE could be measured except at 4 kHz in the first measurement 1 day after birth DPOAE audiogram obtained in the second measurement 13 days after birth indicated normal hearing Two case examples shall illustrate how DPOAE audiograms can reveal temporary sound conductive disorders in the early postnatal period Fehler Referenz nicht gefunden In a 3 days old neonate with a pass response after ATEOAE screen ing the DPOAE audiogram indicated a low frequency hearing loss The DPOAE audogram 83 days later revealed normal hearing function
32. amp RUBEL E W 1994 Variation of distortion product otoacoustic emissions with furosemide injection Hear Res 77 183 99 MULLER J amp JANSSEN T 2004 Similarity in loudness and distortion product otoacoustic emission input output functions implications for an objective hearing aid adjustment J Acoust Soc Am 115 3081 91 MULLER J JANSSEN T HEPPELMANN G amp WAGNER W 2005 Evid ence for a bipolar change in distortion product otoacoustic emissions during con tralateral acoustic stimulation in humans J Acoust Soc Am 118 3747 56 MYERS E N amp BERNSTEIN J M 1965 Salicylate ototoxicity a clinical and experimental study Arch Otolaryngol 82 483 93 NEELY S T GORGA M P amp DORN P A 2003 Cochlear compression estim ates from measurements of distortion product otoacoustic emissions J Acoust Soc Am 114 1499 507 NORTON S J 1992 The effects of being a newborn on otoacoustic emissions The Journal of the Acoustical Society of America 91 2409 2409 NORTON J GORGA M P WIDEN J E FOLSOM R C SININGER Y CONE WESSON B VOHR B R amp FLETCHER K A 2000a Identification of neonatal hearing impairment summary and recommendations Ear Hear 21 529 35 NORTON S J GORGA M P WIDEN J E FOLSOM R C SININGER Y CONE WESSON B VOHR B R MASCHER K amp FLETCHER K 2000b Identification of neonatal hearing impairment evaluation of transient evoked ot
33. and ipsilateral mastoid vertical montage Alternatively to the vertex posi tion forehead position for placing the vertex electrode is possible see Fig la and 1b However in this case ABR amplitude is slightly decreased Despite this fact forehead is preferred in practice especi ally in patients where vertex electrode placement is inconvenient because of hairs Wave I amplitude may be larger in a horizontal montage mastoid to mastoid than in the standard vertical montage vertex to mastoid Reference electrode black is usually placed on the cheek Since Sentiero provides one channel mastoid electrode cable must be changed when using vertical montage of the electrodes If mastoid electrode is not changed ABR is decreased in amplitude at the ear where mastoid electrode cable is connected to the contra lateral ear Common placement of the electrodes for audiological testing Red Mastoid Black e Cheek MYLA Ba OCET 6 2 Perform measurements de i After placing the electrodes electro acoustic transducers headphones or insert phones have to be fitted Important Please make sure that the red transducer is placed at the right ear and the blue transducer is placed at the left ear Plug the ABR cable connector in the white jack Then connect the electrodes with the colored clips as described above red mastoid white vertex or forehead black cheek 39 6 ABR How to use Start the measurement mod
34. atient marks the tone as heard with the patient response button Only for PTA 4 Extended Step 4 gt Then click in the touch screen diagram to confirm the currently selected stimulus level as hearing threshold if the tone was heard Or adjust the stimulus and frequency level shown in step 1 and 2 gt Continue setting the next hearing threshold like shown in step 1 4 OO C Right 102 500 ik 2k 3k 4k 6k skHz gt Press 5 in the screen footer to change the ear red for the right ear or blue for the left ear PTA test results 17 3 PTA How to use Audiogram 0 500 ik 18 2k 3k 4k 6k SkHz Audiogram 0 Soo ik 2k 3k 4k 6k 8kHz PTA test results are displayed as a color coded standard audiogram for the left and for the right ear PTA How to use 19 4 OAE How to use OAEs Otoacoustic emissions are weak sounds generated by the outer hair cells OHCs of the inner ear They are measured by means of a sensitive microphone within a sound probe placed in the outer ear canal Evoked OAEs are generated by either transient clicks and tone bursts or stationary stimuli tones delivered via loudspeakers within the sound probe Transiently evoked OAEs TEOAEs repres ent the sum of the pulse responses of outer hair cells OHCs along the cochlea Distortion product OAEs DPOAEs represent cubic distortions of OHCs when stimulated simultaneously by two tones with frequencies f1 l
35. ces ABDALA C 2000 Distortion product otoacoustic emission 2f1 f2 amplitude growth in human adults and neonates J Acoust Soc Am 107 446 56 BARKER S E LESPERANCE M M amp KILENY P R 2000 Outcome of newborn hearing screening by ABR compared with four different DPOAE pass criteria Am J Audiol 9 142 8 BERG A L SPITZER J B amp GARVIN J H JR 1999 Ototoxic impact of cisplatin in pediatric oncology patients Laryngoscope 109 1806 14 BILGER R C MATTHIES M L HAMMEL D R amp DEMOREST M E 1990 Genetic implications of gender differences in the prevalence of spontaneous otoacoustic emissions J Speech Hear Res 33 418 32 BOEGE P amp JANSSEN T 2002 Pure tone threshold estimation from extrapol ated distortion product otoacoustic emission I O functions in normal and cochlear hearing loss ears The Journal of the Acoustical Society of America 111 1810 1818 BOETTCHER F A amp SALVI R J 1991 Salicylate ototoxicity review and syn thesis Am J Otolaryngol 12 33 47 BONFILS P amp UZIEL A 1989 Clinical applications of evoked acoustic emis sions results in normally hearing and hearing impaired subjects Ann Otol Rhinol Laryngol 98 326 31 BRAY P 1989 Click evoked otoacoustic emissions and the development of a clinical otoacoustic hearing test instrument Dissertation at the University College and Middlesex School of Medicine London 79 11 References 80
36. d see below Two different modes are available MAGIC Audiogram In MAGIC Audiogram mode stimuli are delivered at different stimulus levels Threshold is determined by an automatically controlled bracketing procedure After finishing the test pure tone thresholds are displayed in an audiogram form with areas of different colours indicating different degrees of impairment MAGIC Quick Screen In MAGIC Quick Screen mode the test 1s performed at only one stimulus level screening level which can be selected by the user Stimuli can be delivered via headphones or insert sound probes To get familiar with the test procedure an instruction 1s necessary There are always three animals used for instruction phase The following course of actions is advised 10 Instruction to the child Examiner s task Choose an animal from the Select a stimulus level which is screen expected to be higher than the child s threshold Should be done in settings before starting the test Standard setting is 60 dB Press the animal s belly When pressing the belly the ani mal will make a sound Do you hear the sound Each time you press the belly Ask the child to push the belly the animal makes a sound several times The animal makes a sound but A stimulus level which is 20 dB MAGIC How to use Instruction to the child Examiner s task SI b R 40dB MAGIC the sound is now lower Press
37. d response is indicated if not no response appears on the screen Termination of the measurement by the user stop is indicated by incomplete test Like in TEOAE Diag progress of OAE How to use measurement and noise floor are indicated during measurement Also stimulus sta bility number of rejected frames artefacts and measuring time are displayed Time course and frequency spectrum of the response are shown on the screen during measurement Intended applications of OAEs are as follows e Confirmation of cochlear hearing loss after newborn hearing screening e Assessment of hearing function in infants who are identified at risk for congen1 tal or late onset hearing loss e Frequency specific and quantitative evaluation of mild and moderate hearing loss in infants e Topological diagnostics e Quick test for getting information on hearing capability in preschool and school children e Early detection and monitoring of OHC impairment after noise or ototoxic drug administration e Indisputable proof of a noise induced hearing loss for medical opinions e Identifying persons who are simulation a hearing loss Please note Since OAEs are the by product of the non linear sound amplification process of OHCs in the cochlea they can only serve as a measure for evaluating cochlear inte erity Microphone noise physiological noise breathing blood flow and external noise do not allow proper OAE measurements at low st
38. e pendent deviance of unknown quantity between the nominal sound pressure level at the tip of the ear probe and the actual sound pressure level at the eardrum due to standing wave effects Siegel 1994 This deviation is usually highest at frequen cies corresponding to d A 4 and A 2 d distance between ear probe and eardrum Thus problems become serious around 3 kHz and above 6 kHz in adults but are less important in newborns and infants due to the smaller ear canal length Keefe et al 1993 Calibration errors may cause a change in the shape and thus the compression of DPOAE I O functions Further improvement of ear probe calibration is therefore necessary to enhance the accuracy of clinically rele vant measures deduced from DPOAE recordings such as for example estimated CA threshold and compression 69 9 OAE Description of Methods DPOAE l 0 Function Microphone Spectrum Basilar membrane My Xp L dB SPL 30 w 50 60 L dB SPL L dB SPL A nm eee a PS P 1 ao on DPOAE eS 2 pthreshold Pap Po T 28 i L04 2 9 3 W 50 60 f kHz apikal x mm basal L dB SPL Fig 9 3 Schematic drawing of how to evoke DPOAESs in a way that DPOAEs are able to reflect compressive cochlear sound amplification For yielding best overlap of the travelling wave envelopes primary tone levels L1 blue and L2 red have to be set according to the scissor paradigm L1 0 4 12 39 s
39. e III from cochlear nucleus wave IV and V from lateral lemniscus and inferior colliculus brain stem and wave VI and VII from sub cortical regions Due to the fact that the velocity of the traveling wave running into the cochlea is highest in the basal region click evoked ABRs mirror mainly the activity of basal high frequency cochlear regions This is also true for low frequency tone bursts and chirps when high stimulus levels are applied Wave V has the highest whereas wave I the lowest amplitude Wave amplitudes decreases wave latencies increases with decreasing stimulus level ABRs are a common clinical tool in audiology and neurology Also ABRs are used for new born hearing screening when elicited at a distinct screening stimulus level e g 35 dB nHL Conductive and cochlear hearing loss exhibit different wave amplitude and latency patterns Especially wave V latency and threshold are used for audiological diagnostics in children or handicapped persons who are not able to reliably report on their hearing disability The inter peak latency IPL between wave I and V represent the neural transmission time between cochlea and brainstem IPL is therefore used for assessing retrocochlear pathology eighth nerve and low brainstem lesions It is important to note that due to the maturation of the neural pathway IPL varies during the first year of life The influence of age on ABRs in the elderly is a matter of controversy While some authors have
40. e V latencies varies bet ween about 5 6 ms 80 dB nHL and about 9 ms 10 dB nHL Stan dard deviation of latency is low at the higher stimulus levels approx 0 2 ms at 80 dB nHL and high at the lower stimulus levels approx 0 7 ms at 10 dB nHL Initial stimulus levels higher than 70 dB nHL have to be confirmed prior to measurement Perform measurements 13 40 ABR i Stimulus Averages Plot Range Rate A A A Vv Y 100 0ms Time per trace 2000s Total time 10000s Inter Stimulus Interval 13 34 ABR E gt Age group for normative latencies Newborn O 2 months 6 months O 12 months Adult Don t show normatives O Ask before test 13 41 AB R lt r i gt NEURO 10HZ Rea Select the stimulus rate plot range and the number of averages per response The inter stimulus interval the test duration per response and the esti mated overall test duration will be shown as a result of the settings Changes in stimulus rate affect ABR latency and amplitude With increasing stimulus rate wave amplitudes decrease and wave latencies increase Please note Wave I latency is less affected resulting in an increase of inter peak latencies with faster rates For assessing neural disorders a rate of 10Hz is recommended If wave V is the only com ponent of interest e g threshold determination faster rates can be used With increasing number of averages quality of ABR measurement is
41. e footer To indicate good impedances the color of the impedance value will turn green if it is below 6 kQ Please note In neonates impedance may be higher than 6 kQ because of tenderness of the skin Also unbalanced impedance affects the qua lity of ABR measurements By pressing the play button ABR measurement at the highest selec ted level is started If the play button is not pressed or the impedance remains to high the device stops measuring after some seconds In this case place the electrodes again and restart the test The currently measured response is shown 1n blue All other responses are shown in gray The right top corner indicates the current selected scale 100 to 2000 nV It can be modified by wiping up and down inside the graph area after the measurement or in the result view mode During the measurement the selected levels are shown on the left edge The traffic light symbol to the left of each response indicate its significance If Auto Proceed is selected the device will automati cally proceed with the next measurement when significance of the cur rent measurement was reached which is indicated by the green light You may proceed at any time by pressing the skip button or wait until the maximum recording time per response is reached After the maximum recording time is reached the device proceeds to the next stimulus level By pressing the pause button the measurement is paused a
42. e methods must avoid long preparation times and the test should stop automati cally if the desired quality of the result is achieved TEOAE and DPOAE are widely regarded as being suitable for screening in newborns and infants as they are not present in the case of outer hair cell OHC dysfunction e g Kemp and Ryan 1991 Gorga et al 2000b Norton et al 2000b Norton et al 2000a The premise for this approach is that inner ear hearing loss always includes OHC damage or malfunction Additionally significant conductive losses due to Eusta chian tube dysfunction and or amniotic fluid in the tympanic cavity also cause refer results under screening conditions DPOAE newborn hearing screening is usually performed in the mid frequency region e g between 1 5 and 4 kHz High frequency testing is less reliable due to the standing wave problem and the limitation of the electro acoustic transducer Below 1 kHz the SNR 1s insufficient so that also low frequency testing 1s inadvi sed DPOAEs are elicited at different primary tone levels so that a multi fre Clinical applications of TEOAEs DPOAEs quency and multi level test procedure is provided Extrapolated DPOAE I O func tions are used to estimate hearing thresholds Boege and Janssen 2002 Gorga et al 2003 A therapy for hearing disorder can be developed only after knowing which stage of the auditory pathway is impaired Psychoacoustic tests are able to differentiate bet we
43. e travelling wave along the non functioning basal part of the cochlea at these levels Stimulus rate was set to 20 Hz vertical electrode montage 19 22 ABR e mu 16 18 PTA Result Wave Y SOOM tw E En mn Ss Ho de AG latency ms 0 2 4 6 B 10 12 14 ms Latencies ms IPL ms 1 11 14 MA TO 5 TO fle 1 click level dB nHL Click evoked ABRs in a patient suffering from a severe high frequency cochlear hearing loss at 80 70 60 50 and 40 dB nHL stimulus levels ABR threshold 1s reached at 60 dB dB nHL approximately corresponding to the hearing loss at high frequencies Low frequency thresholds can not be assessed Stimulus rate was set to 20 Hz vertical electrode montage 47 6 ABR How to use Wave V T50ny 80 E Audiogram tee 0 5 1 2 3 4 6 6 125 16k latency ms 0 2 4 6 6 10 12 14 16 ms Latencies ms IPL ms I III 14 MA 80 8 5 80 T 8 6 FO 60 6 0 60 50 50 40 40 30 40 50 60 70 90 click level dB nHL Click evoked ABRs in a patient suffering from a pan tonal frequency cochlear hearing loss at 70 60 50 40 and 30 dB nHL stimulus levels At all stimulus levels with exception of the lowest one latencies are within normal range ABR threshold is reached at 40 dB dB nHL Stimulus rate was set to 20 Hz vertical electrode montage Wave V Audiogram O25 05 1 34 b 8 125 16k latency m s 0 2 4 6 8 10 1
44. ear inner hair cell or neural pathology For example in auditory neuropathy where synchronization of neural activity is malfunctioning either due to inner hair cell synaptic or neural dysfunction normal OAEs and abnormal ABRs occur Doyle et al 1998 Starr et al 1996 OAEs are of course also a suitable means for testing individuals who are only simulating a hearing loss Especially for hearing aid adjustment in infants a quantitative evaluation of the hearing loss and recruitment is necessary When elicited by high stimulus levels which is common in clinical practice TEOAEs are absent at a cochlear hea ring loss exceeding 20 dB HL whereas DPOAEs are absent only at a cochlear hearing loss exceeding 40 50 dB HL Thus when using TEOAEs and DPOAEs elicited at high stimulus levels only a rough estimate of the hearing loss is possi ble For example when TEOAEs are absent and DPOAEs are present then the hearing loss is suggested to be not more than 30 dB HL In principle both DPOAEs and TEOAEs allow acquisition of frequency specific information about a hearing loss problem When stimulating the ear with a click or a tone burst almost all OHCs along the cochlear partition or a part of them the site in the cochlea depending on the carrier frequency of the tone burst are 61 9 OAE Description of Methods 62 excited Due to frequency dispersion in the cochlea a specific component of the TEOAE response can be directly
45. ear function objectively OAEs extend the objective audiometric test battery They allow a direct examination of cochlear function Subjective tests are only able to assess disorders of sound processing as a whole Tympanometry OAEs and auditory brain stem responses ABRs ASSRs in combination allow for a differentiation between sound conductive cochlear and neural hearing loss Minute changes in hearing capability are detectable by OAEs There are four main OAE applications in clinical diagnostics e Newborn hearing screening e Confirmation of a cochlear hearing loss along with tympanometry and auditory brain stem responses e Quantitative evaluation of hearing loss and recruitment for providing hearing aid fitting parameters e Detecting beginning cochlear impairment during noise exposure or ototoxic drug administration Newborn Hearing Screening is a selection procedure used to decide whether fur ther diagnostics are advised or not Wilson and Jungner 1968 Consequently a screening decision is binary pass negative finding no diagnostics necessary or refer positive finding follow up diagnostics advised The requirements for screening are different from those for diagnostics Because screening is performed in large populations the devices used typically provide automatic evaluation rat her than rely on an expert s judgement A screening test should be performed as quickly as possible Therefore the respec tiv
46. els and frequencies is faster than measuring hearing threshold levels When using screen ing PTA the question is whether a person s hearing ability is better or worse than a certain reference level In order to perform screening quickly a restricted num ber of frequencies are tested at predefined levels Calibration of the test environment to meet ambient noise requirements the equipment and the stimuli to ISO standards is needed before testing proceeds PTA only measures thresholds rather than other aspects of hearing 9 OAE Description of Methods 9 1 Types of OAEs The discovery of otoacoustic emissions OAEs Kemp 1978 has produced a totally new tool for diagnosing cochlear function OAEs are the by product of the non linear sound amplification process in the cochlea Davis 1983 Dallos 1992 In sound conductive hearing loss where both the stimulus and the response amplitude are reduced OAEs are difficult to measure even with a mild sound conductive hearing loss Margolis 2002 Along with tympanometry and auditory brain stem responses OAEs can differentiate between middle ear cochlear and neural disorders OHCs are reported to be impaired by sound overexposure ototo xic drugs e g therapeutic antibiotics infections e g meningitis mumps materno fetal infection and anoxia e g birth trauma or to be partly missing in genetic hearing loss OHC impairment results in a loss of sensitivity and fre quency
47. en sound conductive and sensorineural hearing loss by evaluating the diffe rence between sound and bone conductive pure tone thresholds The discrimina tion of a sensorineural hearing loss 1 e the differentiation between a sensory cochlear and a neural disorder with subjective testing is unreliable because the validity of these tests Short Increment Sensitivity Index SISI Fowler Carhart is limited Moreover in non cooperative patients or infants psychoacoustic tests can not be performed In such cases only objective tests help in achieving the goal of determining end organ integrity Using tympanometry OAEs and ABRs ASSRs the site of the impairment in the auditory pathway can be ascertal ned with high reliability OAEs are used primarily as function detectors in clinical practice As a general rule if there 1s a suspicion of a hearing disorder the measurement of OAEs should be used as the first audiological test It is fast and helps to confirm normal middle ear and cochlear function This is the case if OAEs are present over a wide fre quency range If OAEs are absent then middle ear or cochlear OHC pathology is likely OAEs then should be followed by tympanometry If the tympanogram is normal and OAEs are absent then a cochlear disorder is likely If the tympano gram is abnormal a sound conductive hearing loss is likely If both the tympano gram and OAEs are normal ABRs ASSRs are needed to reveal whether there is a cochl
48. en the sound pressure level goes back up in 5 dB steps until the person starts responding again This is conventionally done at 6 octaves at 250 500 1000 2000 4000 and 8000 Hz PTA starts by presenting sound via headphones air conduction or insert sound probes or free field loudspeakers When there is a hearing loss the next step is to determine whether the loss is caused by a sensorineural hearing loss or an outer or middle ear problem This distinction is made by bone conduction where the sound is transmitted to the ear through a bone vibrator placed on the mastoid bone behind the ear In doing this the middle ear is bypassed If there 1s better hearing for bone conduction than for air conduction air bone gap a conductive hearing loss is likely If both air conduction and bone conduction thresholds are out of the normal range a sensorineural cochlear or retro cochlear impairment 1s likely To differentiate a detected sensorineural hearing loss supra threshold testings 55 8 PTA Description of Methods 56 Fowler Carhart loudness scaling etc have to be performed OAEs and auditory brain stem potentials are important tests for a topological diagnostic Bone conduction testing in persons with hearing loss must be done with masking the opposite ear to prevent sound from the stimulated side from going over to the good side cross hearing The threshold of the test ear is measured at the same time as presenting the masking no
49. ends with high fre quency signals see time domain Fig 2a red line Using this rising frequency chirp the decrease of the travelling wave velocity along the basilar membrane is compensated resulting in an enhancement of the synchrony of neural activity and with that in higher response amp litudes Chirp provides a broader frequency band compared to that of the click see frequency domain Fig 2a blue and red line Select polarity Condensation C Rarefaction R or Alterna ting A Single polarity stimuli C or R produce different initial movement of the basilar membrane Initial firing of the nerves coincides with R sti muli resulting in different wave latencies and amplitudes with C and R Thus different waveform morphology appears when using single or alternating polarity clicks Single polarity click stimulation may evoke wave I with higher ampli tude However when using single polarity clicks the electrical signal of the electro acoustic transducer interferes with the ABR Therefore A click stimuli are preferred especially when using headphones When using insert phones electrical artifacts are lower Select Jitter Jitter will add a small random change in stimulus rate which can reduce the sensitivity to certain electrical interference ABR amplitude is known to be decreased at a constant stimulus rate due to adaptation By enabling Jitter adaptation is reduced Select Masking noise
50. erence of the second DPOAE source makes the interpretability and the accuracy of deduced measures such as DPOAE thres hold and compression difficult There have been attempts to minimize the influ ence of the second source by presenting an additional suppressor tone near 2 1 f2 Heitmann et al 1998 or by using a time windowing procedure which is able to separate the two sources Mauermann and Kollmeier 2004 The measured OAE presssure in the outer ear canal depends on the ear canal volume Because of the smaller ear canal volume OAE pressure in newborns is higher compared to that of adults Norton 1992 Lasky 1998b Lasky 1998a Abdala 2000 As a consequence OAEs in newborns are easier to measure 9 5 TEOAE DPOAE stimulus setting TEOAE responses can be evoked by two types of stimulus trains 1 by a set of four clicks of equal magnitude referred to as the linear protocol or 11 by three clicks of positive polarity followed by a fourth click of an inverse polarity with a relative magnitude of 9 5 dB higher than the corresponding positive clicks refer red to as the non linear protocol Kemp et al 1986 Bray 1989 Under the hypothesis that the TEOAE recordings originate from saturated cochlear genera tors it is assumed that the non linear protocol removes stimulus artifacts of a linear nature 1 e the stimulus itself because sound signals increase linearly with 67 9 OAE Description of Methods 68 the sti
51. eth ods in praxis in separate chapters Part II describes general aspects of the meth ods 1 Overview This How To Manual is providing additional information on Senti and Sentiero seen from a daily use perspective from the end user It does not replace the user manual which is provided together with the device and which already describes the function of the device Sentiero offers both psycho acoustical and physiological test procedures which are based on conventional and image based pure tone audiometry speech logatome intelligibility and otoacoustic emissions Psycho acoustical test modules are e MAGIC Multiple choice Auditory Graphic Interactive Check Image based and self controlled pure tone audiometry e PTA Pure Tone Audiometry Conventional pure tone audiometry class 3 4 audiometer e SUN Speech Understanding in Noise Vowel Consonant Vowel logatome test Physiological test modules are e DPOAE Threshold Estimating hearing loss by means of extrapolated DPOAE I O functions e Quick DPOAE Indicating the presence of a valid DPOAE at one ore more selected primary tone levels e TEOAE Diag Performing conventional click evoked otoacoustic emissions measurments 1 Overview e TEOAE Quick Performing TEOAE measurement by using an automated statistical algorithm for response detection Please note Placement of the transducers is important Variation in earphone position up down or front back and leakage bet
52. evels and frequencies Return to OAE selection A calibration of the ear probe will first be performed before the measurement starts gt gt gt gt gt gt If the probe is not placed properly in the ear canal the message incomplete will appear on the display In this case please correct the e position of the probe S muus p Response M a 97 Incomplete The following speaker test detects the proper functionality of the speakers After the tests the measurement starts automatically by scanning L2 35 dB HL the cochlea at the selected primary tone level s L and at up to six frequencies 1500 2000 3000 4000 6000 and 8000 Hz gt Press to interrupt the test gt Press to continue the test after pausing f2 15 2 3 4 6 Progress p gt Press Qto skip a frequency PA 4 OAE How to use gt progress bar measuring time gt noise bar surrounding noise After the measurement the measuring points of the single frequencies appear in logar ithmic representation gt Vertical bars indicate the validity of the DPOAE response at the corresponding frequency f2 gt If the vertical bar reaches the top of the box the response con tains a valid DPOAE signal according to the criterion gt The color of the vertical bar corresponds to the standard color of the tested ear red right ear blue left ear Quick DPOAE test results Ru O oE A gt valid DPOAE
53. f the difference between image based and play audiometry thresholds showed normal distribution Mean and standard devi ation of the differences amounted to 1 5 dB and 9 6 dB respectively Test time per frequency one ear was on average about 30s ranging from 14s to 91s Test time decreased with increasing age 8 PTA Description of Methods Pure tone audiometry PTA is the testing of a person s ability to hear various sound frequencies The test is performed with the use of an audiometer Otoscopy should be done prior to PTA to determine if there are any blockages in the ear canal due to ear wax Before the test the subject has to be instructed about the task As PTA is a psycho acoustical test method the ability willingness and con centration of the subject to co operate are essential Also placement of the trans ducers is important Variation in earphone position up down or front back and leakage between earphone and ear may give rise to falsely poor hearing threshold levels particularly at the highest frequencies Hearing is commonly measured at frequencies varying from low 250 Hz to high sound frequencies 8 kHz It should be emphasized that this is just a part of the entire human auditory range which extends between 20 Hz and 20 kHz The core method of PTA is to present a pure tone close to threshold and keep dropping the intensity in 10 dB steps until the person stops responding raising their hand or pushing a button Th
54. frequencies Cow 250 Hz bear 500 Hz elephant 1 kHz cat 2 kHz sheep 3 kHz mouse 4 kHz bird 6 kHz dolphin 8 kHz Each ani mal is presented in three variants Neutral to start the sound presentation heal thy and sick for indicating the two conditions heard and not heard Before measurement a story is told such that the child is instructed that healthy animals will make sounds and sick animals are not able to The child has the task to decide and categorize So the child is the doctor This can also help to put off the pres sure of the child because it s not him her to be diagnosed but he she will diagnose the animals ability to give sounds The child has the task to decide and categorize So the child is the doctor The test procedure progress is visualized by a shelf from which the current test animal is selected The test 1s controlled by the child itself via touch screen This includes sound presentation as well as input if the sound was heard healthy animal or not sick animal The examiner can supervise the measurement and assist the child with the entry when indicated The examiner can also intervene in the measure ment procedure at any time or can do a retest at any frequency whenever necessary 2 MAGIC How to use Please note Children which are not expected to be able to perform the test or are not able to react to the sound in a proper way DPOAE Threshold measurement is advise
55. g sound probe position amounted to about 1 6 dB Muller et al 2005 DPOAEs are supposed to primarily reflect OHC activity at the fp place However there is evidence that DPOAEs are generated by two distinct cochlear sources Whitehead et al 1992 Brown et al 1996 Shera and Guinan 1999 As already mentioned the first source the effect of which is actually intended to be measu red is located at the region of overlap of the traveling waves of the two prima ry tones near the f2 place and 1s due to intermodulation distortion The second source which is unintentionally adding to the first source emission is located at the characteristic frequency place of the emission at 2f1 f2 and is due to reflection of energy that has travelled apically from the overlap region near f2 Thus energy from both interacting sources yield the composite DPOAE signal which is actually recorded in the outer ear canal The influence of the second DPOAE source may be observed when monitoring the DPOAE level across frequency with narrow fre quency spacing of f2 DPOAE fine structure Due to either destructive or con structive superposition of the two DPOAE sources across frequency a number of investigators have described a pattern of dips and peaks in the DPOAE fine struc ture in normal hearing subjects He and Schmiedt 1993 He and Schmiedt 1996 He and Schmiedt 1997 Talmadge et al 1999 However for clinical evaluation of DPOAE I O functions the interf
56. gher frequency DPOAEs arise directly from the frequency selective compressive non linearity of OHCs Brownell et al 1985 Kemp et al 1986 The two tones inter act in the cochlea close to the characteristic place of f2 Thus DPOAEs can be applied as a probe for frequency specific assessment of cochlear dysfunction at the f2 place In humans the 2 1 2 distortion component yields the highest amplitude and is therefore primarily used in audiological diagnostics Gorga et al 2000a DPOAEs are reported to be measurable at a cochlear hearing loss of up to 40 50 dB HL representing approximately the range of the cochlear amplifier Davis 1983 Ruggero et al 1997 TEOAEs and DPOAEs are present in essentially every normally hearing subject Stimulus frequency OAEs SFOAESs are elicited by one continuous low level sinusoidal signal Recording of SFOAEs 1s difficult because stimulus and response superimpose Whereas TEOAEs more qualitatively assess cochlear function DPOAKs provide quantitative information about the range and operational characteristics of the cochlear amplifier CA 1 e sensitivity compression and frequency selectivity There are several DPOAE measures which are used for assessing the functioning of the CA DPOAE grams plot the DPOAE level Ldp as a function of f2 the main DPOAE generation site for a selected combination of the primary tone levels L1 and Z2 It should be emphasized that DPOAE grams reflect CA sensitivi
57. gned to assess the listening difficulty most commonly experienced by adults 1 e to understand speech in noise To minimize the duration of the test procedure the sequence of stimuli presented in SUN test 1 e the set of VCVs has a fixed length and the presentation levels of the test sti muli and noise are pre determined To minimize the cognitive load the task of recognizing the stimuli in the SUN test is simplified by offering to the subject only three choices for each VCV Three alternative forced choice procedure is used Test person has to select via touch screen three alternative VCVs e g aFa aGa aSa VCVs are presented via headphones at different signal to noise ratios The test gives a tri modal outcome hearing ability within normal range hearing ability might be below the normal range hearing ability might be well below the normal range Intended us of the SUN test is to assess speech understanding in noise The test was specifically designed for the early detection of age related hearing loss For description and evaluation of the test see Paglialonga A Tognola G Grandori F 2011 SUN test Speech Understanding in Noise a method for hearing disability screening Audiology Research 1 e13 Title journal etc Grandori et al 2011 However the SUN test can also be used as a self controlled speech test for school children Speech stimuli can be delivered via headphones insert sound probes or free field loudspeaker
58. h a valid response occurs 1s now used as reference to the estimated threshold For eliciting DPOAEs a special parameter setting scissor paradigm is used which accounts for the different compression of 21 4 OAE How to use 2 the primary tones on the basilar membrane for more detail see How To Manual Part II Progress of measurement and noise floor are indicated for current measu rement Filled vertical bars indicate at which levels valid DPOAE were measura ble Open box symbol indicates at which frequency and level DPOAE measure ment is running Estimated thresholds are presented in an audiogram form DPOAE audiogram Type of estimation is indicated by different symbols In con trast to TEOAEs common DPOAEs and click evoked brain stem potentials DPOAE audiograms are able to quantitatively assess the hearing loss Test time for establishing a DPOAE audiogram takes a couple of minutes only Thus DPOAE audiograms can serve as a new tool for bridging the gap between scree ning and audiological testing Clinical application of DPOAE audiograms are pre sented and discussed in How To Manual Part II DPOAE Quick for measuring DPOAEs at user defined test frequencies and levels Frequencies and levels can be chosen from a frequency level matrix Two different protocols are available Screening at a selected screening level and individual diagnostic multiple selections of stimulus parameters Progress of measurement and noise fl
59. hod is based on the calculation of the buffer correlation of the time domain averaged signals between two separate signal buffers Kemp et al 1990a If the two buffers are completely identical the correlation coefficient is 1 and thus the reproducibility 100 A signal is commonly accepted as valid for a reproducibility exceeding a minimum of 60 The second method relies on the computation of the spectral power ratio of the sum and the difference of the two signal buffers denoted as the signal to noise ratio SNR The pass criterion for a valid signal is typically set to an SNR of 6 dB The third signal validation proce dure is based on a binomial statistical test which determines the statistical proba bility that an emission has been recorded Binomial statistics reduces the recorded signal to binary events and uses knowldge on the expected distribution of these events binomial distribution Giebel 2001 In the case of DPOAEs commercially available systems perform mainly two dif ferent data validation procedures The first method is based on the calculation of the noise floor level by averaging the levels of several adjoining frequency com ponents around the DPOAE frequency component with the SNR being indicated by the difference between the emission level and the noise floor level Here also the SNR criterion is usually set to 6 dB The second data validation procedure is based on a phase statistics method which checks the coupling of
60. imulus levels At lower frequen cies OAE measurements are not reliable even at high stimulus levels To achieve low noise floor levels OAE measurements have to be done in a sound attenuating booth especially when close to threshold stimulus levels are used Make sure that insertion of sound probe must be done without any leakage bet ween sound probe and ear canal Leakage is indicated during calibration procedure which is done automatically If there is leakage low frequency sound components can not be delivered to the cochlea properly and hence no apical and medial OHCs will contribute to OAE response Blockage of sound probe ports is indicated when performing calibration Be aware that high frequency TEOAE components get lost as a result of the win dowing procedure which 1s done for excluding stimulus sound components from the response As a result OHC functionality can not be determined in the basal region of the cochlea when using TEOAEs Therefore a high frequency hearing loss can not be detected by TEOAEs Also note that valid TEOAE responses can be present in ears with a mid frequency hearing loss e g congenital hearing loss The problem with TEOAEs here is that infants with congenital hearing loss are 23 4 OAE How to use overseen and the hearing loss is detected later in life In general to get more fre quency specific and quantitative information on the hearing loss it is advised to perform DPOAE threshold measurements
61. increased In quiet subjects and at good measuring conditions 2000 averages may be sufficient If there is high muscle activity high elec trode impedance ambient acoustical and electrical noise the number of averages has to be considerably increased especially at close to threshold stimulus levels Select age group Several groups can be selected Newborn 2 month 6 month 12 month Adult The selection will only affect the normative latency range which is dif ferent for the different age groups Latency ranges are shown with the responses Further age group options Don t show normatives Ask before test By pressing Edit Preset Name the preset can be renamed Type in the new preset name by using the screen keyboard Confirm your input with enter Continue Measurement 43 6 ABR How to use 13 56 ABR lt r Hi y Impedance Progress MEN vac E open 13 50 ABR Hr j Impedance Progress ppm aji Mm 1 6k 13 52 ABR LF 80 A El e O 60 40 0 2 4 6 8 10 ms EEG PU Impedance 1 5k Progress PA E 1 6k 13 54 ABR e gt 84 ANA at c Ti s Electrode impedance is too high The test will now pause 41 You may re place the electrodes and continue the test S OK i 44 Before ABR measurement starts electrode impedance is checked When the impedance is within an acceptable range below 12 kQ a play button appears in th
62. ion of the probe Response S muus p The following speaker test detects the proper functionality of the speakers DPOAE I O functions are measured at the following frequencies 1 5 2 3 4 6 and 8 kHz Before the measurement of each frequency stars a fine adjustment is performed in order to check at which frequency the emission can best be recorded DPOAE I O functions are measured from L2 65 dB SPL in 10 dB steps decreas ing to L2 15 dB SPL If several values are measured a line of values is displayed running from the bot tom high L2 to the top low L2 L2 1s reduced for as long as a DPOAE response occurs If no response is recorded L2 is increased automatically until 5 values are identified For the estimation of the hearing threshold are needed at least three measuring points 10 45 DPOAE E f2 6000 Hz L2 40 dB Overview DPOAE 6 kHz Progress AB Noise NON AAAA 25 4 OAE How to use Display during measurement f2 current frequency L2 current level time out progress bar measuring time noise bar surrounding noise open box symbol current measuring point filled vertical bars previous valid measurement data gt Press PAUSE to interrupt the test gt Press CONT to continue the test gt Press to skip a frequency The measurement will continue with a 5 dB lower level or with the next frequency gt Vertical green bar validity of the DPOAE response at the curre
63. ise to the non test ear Thus thresholds obtained when masking has been applied provide an accurate representation of the true hearing threshold level of the test ear A reduction or loss of energy occurs with cross hearing It varies from 40 dB to 80 dB with supra aural headphones However with insert earphones it is in the region of 55 dB The use of insert earphones reduces the need for masking The threshold is plotted across test frequencies on a graph audiogram In case of air conduction the right ear is usually plotted in red using an x symbol and the left in blue using an o symbol In case of bone conduction the right ear is indic ated by a lt unmasked or masked symbol the left ear by a gt unmasked or symbol unmasked Hearing loss is described in words as fol lows e Normal hearing lt 25 dB HL adults lt 15 dB HL children e Mild hearing loss 25 40 dB HL e Moderate hearing loss 41 65 dB HL e Severe hearing loss 66 90 dB HL e Profound hearing loss 90 dB HL In screening PTA the test results show whether the hearing threshold levels are better equal to or worse than the screening level used The test tone is delivered to the ear at frequencies and intensity levels that have been chosen for the screen The subject passes the screening test according to predefined criteria e g a pass occurs if all tones are heard in each ear Screening at certain selected lev
64. mulus level while sound signals increasing non linearly with the stimulus level 1 e the emission emerging from the non linear operation of OHCs remain It is generally accepted that the non linear protocol is a practical compromise to maximize the reliability of a TEOAE recording Kemp et al 1990a Kemp et al 1990b Grandori and Ravazzani 1993 Von Specht et al 2001 Hatzopoulos et al 2003 When using the scissor primary tone setting Fig 9 2 which accounts for the different compression of the primary tone traveling waves at the f2 place Whitehead et al 1995c Whitehead et al 1995a Kummer et al 2000 Boege and Janssen 2002 the DPOAE I O function reflects compressive non linear sound processing known from direct measurements of basilar membrane displa cements Ruggero et al 1997 Due to the steep slope of the traveling wave towards the cochlear apex the maximum interaction site is close to the f2 place in the cochlea Thus OHCs at the f2 place contribute most to DPOAE generation The number of OHCs contributing to DPOAE generation depends on the size of the overlapping region which is determined by the primary tone levels L1 and L2 respectively and the frequency ratio f2 f1 of the primary tones fl und f2 To pre serve optimum overlap of the primary tone traveling waves at a constant fre quency ratio f gt f 1 2 the primary tone level difference has to be increased with decreasing stimulus level resulting in
65. n MAGIC test results mease em gt gt Test results are displayed in a color coded audiogram Audiogram k 3k 4k 6k 8k gt Press 2St to do a retest The test results will be stored gt The test results will be saved automatically 13 2 MAGIC How to use Audiogram 250 500 ik 2k 3k 4k 6kHz Audiogram 250 500 ik 2k 3k 4k 6kHz gt Question marks 1 for right ear or 1 for left ear appear underneath the audiogram if a muted animal was marked as heard during the measurement phase a E E E gt The figure underneath the question mark displays the num ber of these answers gt Select the frequency and the ear left or right Retest Frequency Hz Left Right a zj gt To do the retest at selected frequency levels and selected 1k ear s confirm data black arrow 2k 3k s Ed gt The test results will be saved 8k O a e a gt Press the green arrow to quit the screen 14 3 PTA How to use PTA Pure tone audiometry is the key hearing test to identify hearing threshold levels of an individual enabling determination of the degree type conductive or sensorineural and configuration of a hearing loss PTA is a subjective behavi oural measurement of hearing threshold as it relies on patient response Therefore PTA is used on adults and children old enough to cooperate with the test proced ure Usually PTA 1s performed by using an audiometer in the
66. n estimate of the DPOAE threshold level At test frequencies where DPOAEs are only present at two L2 levels or one L2 level no extrapola tion is done In this case the estimated threshold is calculated by the lowest L2 L2min at which a valid DPOAE could be achieved minus 15 dB After converting SPL in HL a DPOAE audiogram is constructed Circle means threshold estimation by means of extrapolated DPOAE I O functions square symbol means simplified estimation L2min 15dB arrow sym bol means no DPOAE are measurable and thus the hearing loss is estimated to be higher than 50 dB HL A major disadvantage of using OAEs in screening protocols is a lower validity as compared to ABR methods Norton et al 2000b Barker et al 2000 This is especially true in populations with a high prevalence of slight threshold elevation due to a temporary sound conductive hearing loss as it is found in term neonates in the first 36 hours of life because of Eustachian tube dysfunction or amniotic fluid in the tympanic cavity or due to a persisting sensory hearing loss in premature and neonatal intensive care unit infants In order to maintain a high sensitivity the spe cificity may be reduced dramatically making a screening procedure inefficient To avoid high referral rates OAE referrals should be followed up with an ABR screening before diagnostic assessment 1 e two stage screening Rhodes et al 1999 Norton et al 2000a DPOAE audiograms may be an
67. nd the pause button changes to the play button To continue press play During the measurement the electrode impedance is measured periodi cally If the value is too high the measurement is paused and a mes sage Electrode impedance is too high The test will now pause You may re place the electrodes and continue the test is shown Perform measurements 13 54 ABR gt i KODIR 0 2 4 6 8 10 ms EEG ES impedance 1 5k Progress ZT mM 1 6k 16 13 ABR lt H gt 0 2 4 6 8 10 12 14 ms Latencies ms IPL ms I III I V M1 50 50 ES 40 gt 40 30 20 10 0 2 4 6 8 10 12 14 ms Latencies ms IPL ms I III I V M1 0 62 50 In this case re place the electrodes and press the play button to con tinue within the maximum recording time per response When the measurement has finished the ABR result panel is displayed which shows the responses at all selected stimulus levels You may modify the scale by wiping up and down inside the graph area The traffic light symbols to the left of each response indicate its statistical significance providing a suggestion for the responses to be valid If wave peaks were marked the available absolute latencies wave I wave III wave V and relative latencies IPL will be shown in the lower panel Different IPLs can be selected Wave I III wave II V and wave I V Press the table area to display ei
68. ning Audiology Research 1 e13 The test aims at logatome recognition specifically at the identification of consonants and hence at the early assessment of age related hearing loss The test 1s fully automated using a three alternative forced choice procedure in which three alternative VCVs e g aFa aGa aSa from a set of 12 items are displayed on a touch screen VCVs are presented via headphones at different signal to noise ratios Test person has to select the correct item from the screen The test gives a tri modal outcome hearing ability within normal range score gt 9 12 hearing ability might be below the normal range score equal to 7 or 8 hearing ability well below the normal range lt 6 12 Otoscopy should be done prior to the test to determine if there are any blockages in the ear canal due to ear wax Before the test the subject has to be instructed about the task As SUN is a psycho acoustical test method the ability willingness and concentration of the subject to co operate are essential Also proper place ment of the transducers and low ambient noise conditions are important for a reli able outcome Preliminary findings of a study on more than 1000 subjects suggests SUN to be suited for adult hearing screening because test time is short 2 minutes on average cognitive load is low and acceptability of test persons is high see Paglialonga et al 2011 del 10 SUN Description of Methods 78 1 1 Referen
69. nse equalled the noise present in the instrument Dorn et al 2001 However since the noise 1s of technical origin e g microphone noise the thres hold evaluated in this way does not match the behavioural threshold A more rele vant measure is the intersection point between the extrapolated DPOAE I O func tion and the primary tone level axis at which the response s sound pressure is zero and hence at which outer hair cell amplifiers are inactive Boege and Janssen 2002 Gorga et al 2003 A linear dependency between the DPOAE sound pres sure and the primary tone sound pressure level is present Boege and Janssen 2002 when using the scissor paradigm for eliciting DPOAEs Kummer et al 2000 Because of the linear dependency DPOAE data can be easily fitted by linear regression analysis in a semi logarithmic plot where the intersection point of the regression line with the L2 primary tone level axis at pdp 0 Pa can thus serve as an estimate of the DPOAE threshold The estimated DPOAE threshold Ldpth is independent of noise and seems to be more closely related to behavioural threshold than the DPOAE detection threshold Boege and Janssen 2002 Gorga et al 2003 Janssen et al 2006 Extrapolated DPOAE I O functions are used to determine DPOAE thresholds which can be displayed on in an audiogram form DPOAE audiogram Circle symbol means threshold estimation by means of extrapolated DPOAE I O func tions square symbol means
70. nt stimulus frequency and level started at the top of the screen gt Ifa DPOAE response was identified as being valid the vertical bar at the respective frequency is extended to the corresponding primary tone level L gt The colors of the vertical bars in the diagram correspond to the standard color of the tested ear red right ear blue left ear DPOAE Threshold test result The DPOAE Audiogramm displays the estimated hearing threshold at differ ent frequencies 10 45 DPOAE Result z 1007 DPOAE Result E gt back to test result list DPOAE Threshold DPOAE Threshold 15 2 3 4 E 8 kHz 15 2 3 4 6 8 kHz An arrow pointing down from the 50 dB line indicates that no sufficient emissions could be measured in order to fulfill the criterion A hearing loss greater than 50 dB could be the case 26 OAE How to use Note In case DPOAEs are missing we recommend verifying the status of the middle ear with a tympanogram DPOAE Quick DPOAE quency Hz enc 3k 4k 6 21 04 DPOAE gt i Fie 1 5k 2k 3k k k O Y Y E E El VY L2 25dB HL E L2 30 dB HL E 12 45dB HL E L2 50 dB HL gt Press AX to select the frequencies you want to test la gt To start the measurement please choose between right and left ear Select level and Quick DPOAE measurement Select primary tone level L A single level or up to six different levels can be selected at once ow confirm the selected l
71. ntial dependence on stimulus parameters J Acoust Soc Am 91 1587 607 WHITEHEAD M L MCCOY M J LONSBURY MARTIN B L amp MARTIN G K 1995a Dependence of distortion product otoacoustic emissions on primary levels in normal and impaired ears I Effects of decreasing L2 below L1 J Acoust Soc Am 97 2346 58 WHITEHEAD M L STAGNER B B LONSBURY MARTIN B L amp MAR TIN G K 1995b Effects of ear canal standing waves on measurements of distor tion product otoacoustic emissions J Acoust Soc Am 98 3200 14 WHITEHEAD M L STAGNER B B MCCOY M J LONSBURY MARTIN B L amp MARTIN G K 1995c Dependence of distortion product otoacoustic emissions on primary levels in normal and impaired ears II Asymmetry in L1 L2 space J Acoust Soc Am 97 2359 77 WIER C C PASANEN E G amp MCFADDEN D 1988 Partial dissociation of spontaneous otoacoustic emissions and distortion products during aspirin use in humans J Acoust Soc Am 84 230 7 WILSON J amp JUNGNER G 1968 Principles and practice of screening for dis ease World Health Organization WHO Geneva ZWICKER E amp SCHLOTH E 1984 Interrelation of different oto acoustic emissions J Acoust Soc Am 75 1148 54
72. o the OAE literatur is also included MAGIC and SUN are new tests Only a few references to these tests are available Performance of conventional pure tone audiometry is described without references to the literatur 50 ABR case examples 51 MAGIC Description of Methods MAGIC Multiple choice Auditory Graphic Interactive Check is a new image based self controlled test for determining pure tone thresholds in playful way Preliminary findings concerning feasibility and reliability of the test in children are described in a multi centre study conducted at Department for Communication Disorders ENT Department of the University of Mainz Medical School s hospital Germany at the ENT clinic of Klinikum rechts der Isar Technische Universitat Munchen Germany and at Cyprus Audiology Center Nicosia Cyprus Schir konyer et al Y DGPP gt please also refer to our scientific publications on the support page or get into contact with us Measurements were conducted in 108 children aged between 3 6 11 11 years at the frequencies 0 5 1 2 4 kHz n 82 and additionally at 0 25 3 6 8 kHz n 26 using Sentiero PATH medical Different animals represented different fre quencies bear 500 Hz elephant 1 kHz etc Each animal was present in three variants Neutral to start the sound presentation happy healthy and sad sick for indicating the two conditions heard and not heard Before measurement a story was told s
73. oacoustic emission distortion product otoacoustic emission and auditory brain stem response test performance Ear Hear 21 508 28 PENNER M J GLOTZBACH L amp HUANG T 1993 Spontaneous otoacous tic emissions measurement and data Hear Res 68 229 37 PENNER M J amp ZHANG T 1997 Prevalence of spontaneous otoacoustic emissions in adults revisited Hear Res 103 28 34 PICTON T W JOHN M S DIMITRIJEVIC A amp PURCELL D 2003 Human auditory steady state responses Int J Audiol 42 177 219 References PROBST R LONSBURY MARTIN B L MARTIN G K amp COATS A C 1987 Otoacoustic emissions in ears with hearing loss Am J Otolaryngol 8 73 81 RHODES M C MARGOLIS R H HIRSCH J E amp NAPP A P 1999 Hear ing screening in the newborn intensive care nursery comparison of methods Otolaryngol Head Neck Surg 120 799 808 ROBINETTE M S amp GLATTKE T J 2002 Transient evoked otoacoustic emis sions In ROBINETTE M S amp GLATTKE T J eds Otoacoustic emissions clinical applications 2 ed ed New York Thieme ROESER R J 1996 Roeser s audiology desk reference A guide to the practice of audiology New York Stuttgart Thieme RUGGERO M A RICH N C RECIO A NARAYAN S S amp ROBLES L 1997 Basilar membrane responses to tones at the base of the chinchilla cochlea J Acoust Soc Am 101 2151 63 SHERA C A amp GUINAN J J JR 1999 Evoked
74. olid lines For comparison travelling wave envelopes are shown for L1 L2 condition dotted lines The L1 and L2 spectral lines are shown for the scissor paradigm solid line and the L L gt paradigm dotted line DPOAEs same data are plotted in a double log arithmic L across L2 and semi logarithmic scale p across L2 Inter section of the linear regression line with L2 axis serves as an estimate of DPOAE threshold level In testing TEOAEs calibration errors have less impact because the wide band sti mulus is not influenced that strongly by standing wave problems Apart from this TEOAESs are usually stimulated with a click level that is relatively high 1 e where cochlear compression already saturates cochlear motion As opposed to DPOAEs no level ratio between primary tones needs to be fulfilled This results in TEOAEs being less susceptible to stimulus calibration errors 9 7 Relation between DPOAEs and behavioural pure tone thresholds 70 The relation between DPOAE level and behavioural pure tone threshold or rather the lack of it is strongly debated Earlier it was common to define confid ence limits to determine the degree of certainty with which any measured response could be assigned to either normal or impaired hearing Gorga et al 1996 Gorga et al 2000a or to define a DPOAE detection threshold as the stimulus level at Relation between DPOAEs and behavioural pure tone thresholds which the respo
75. oor are indicated for current measurement Increasing vertical bars show if there is a valid response at the different test frequencies DPOAEs are measured auto matically at the different test frequencies However test frequencies can be skip ped by the examiner Results are displayed in the frequency level matrix indica ting valid invalid and skipped measurements TEOAE Diag for measuring TEOAEs in a time window of 3 to 13 ms at a fixed stimulus level Progress of measurement and noise floor are indicated during measurement Also stimulus stability and number of rejected frames artefacts are displayed Criteria for proving response as valid can be chosen in five half octave bands their centre frequencies being 1 1 5 2 3 and 4 kHz This is done by setting a specific signal to noise ratio 3 6 or 9 dB for each frequency band Time course and frequency spectrum of the response are shown on the screen Also noise and SNR are indi cated for the different frequency bands If the test criterion is reached valid response if not no response appears on the screen Termination of the measure ment by the user stop is indicated by incomplete test It is a common rule in clinical practice to yield a stimulus stability of more than 80 Artefacts shall be lower than 20 TEOAE Quick When running TEOAE Quick criteria for proving response as valid are fixed no user defined criteria If the test criterion is reached vali
76. otoacoustic emissions arise by two fundamentally different mechanisms a taxonomy for mammalian OAEs J Acoust Soc Am 105 782 98 SIEGEL J H 1994 Ear Canal Standing Waves and High Frequency Sound Cal ibration Using Otoacoustic Emission Probes Journal of the Acoustical Society of America 95 2589 2597 SMURZYNSKI J amp KIM D O 1992 Distortion product and click evoked otoacoustic emissions of normally hearing adults Hear Res 58 227 40 STARR A PICTON T W SININGER Y HOOD L J amp BERLIN C I 1996 Auditory neuropathy Brain 119 Pt 3 741 53 STAVROULAKI P APOSTOLOPOULOS N SEGAS J TSAKANIKOS M amp ADAMOPOULOS G 2001 Evoked otoacoustic emissions an approach for monitoring cisplatin induced ototoxicity in children nt J Pediatr Otorhino laryngol 59 47 57 TALMADGE C L LONG G R TUBIS A amp DHAR S 1999 Experimental confirmation of the two source interference model for the fine structure of distor tion product otoacoustic emissions J Acoust Soc Am 105 275 92 VON SPECHT H GANZ M PETHE J LEUSCHNER S amp PYTEL J 2001 Linear versus non linear recordings of transiently evoked otoacoustic emissions methodological considerations Scand Audiol Suppl 116 8 85 11 References 86 WHITEHEAD M L LONSBURY MARTIN B L amp MARTIN G K 1992 Evidence for two discrete sources of 2f1 f2 distortion product otoacoustic emis sion in rabbit I Differe
77. otoxicity Ear Hear 15 232 9 GIEBEL A 2001 Applying signal statistical analysis to TEOAE measurements Scand Audiol Suppl 130 2 GORGA M P NEELY S T DORN P A amp HOOVER B M 2003 Further efforts to predict pure tone thresholds from distortion product otoacoustic emis sion input output functions J Acoust Soc Am 113 3275 84 GORGA M P NELSON K DAVIS T DORN P A amp NEELY S T 2000a Distortion product otoacoustic emission test performance when both 2f1 f2 and 212 fl are used to predict auditory status J Acoust Soc Am 107 2128 35 GORGA M P NORTON S J SININGER Y S CONE WESSON B FOL SOM R C VOHR B R WIDEN J E amp NEELY S T 2000b Identification of References neonatal hearing impairment distortion product otoacoustic emissions during the perinatal period Ear Hear 21 400 24 GORGA M P STOVER L NEELY S T amp MONTOYA D 1996 The use of cumulative distributions to determine critical values and levels of confidence for clinical distortion product otoacoustic emission measurements J Acoust Soc Am 100 968 77 GRANDORI F amp RAVAZZANI P 1993 Non linearities of click evoked otoacoustic emissions and the derived non linear technique Br J Audiol 27 97 102 GRANDORI F TOGNOLA G amp ALESSIA P A speech in noise test for screening hearing ability in adults the Speech Understanding in Noise SUN test Auris Nasus Larynx submitted
78. otoxicity is important for pro viding effective management options such as substitution of medications change of dosage and mode of administration Lonsbury Martin and Martin 2001 Because TEOAEs are less effective above 4 kHz DPOAEs are the test of first choice for detecting and monitoring OHC dysfunction due to ototoxic drugs Moreover DPOAEs have an additional advantage over TEOAEs in that they can give information about compression of the OHC amplifiers If OHC function is disturbed during the toxic process then not only DPOAE level but also DPOAE 63 9 OAE Description of Methods growth should be altered Like anitibiotic and chemotherapeutic drugs salicylate is also known to affect hearing sensitivity and to induce tinnitus Myers and Bernstein 1965 McFadden and Plattsmier 1984 Wier et al 1988 Long and Tubis 1988 Boettcher and Salvi 1991 Brown et al 1993 McFadden and Pasa nen 1994 However most importantly impairment due to salicylate toxicity is reversible Assuming that a loss of OHC stiffness is responsible for distortions within cochlear micromechanics the corresponding tonic change at the inner hair cell activity may be one potential correlate of tinnitus Janssen et al 2000 Since OAEs directly reflect OHC dysfunction they are therefore the method of choice in occupational medicine where the indisputable proof of a cochlear hea ring loss is required 9 3 TEOAE DPOAE recording 64 OAEs are
79. ower frequency and f2 higher frequency DPOAEs arise directly from the frequency selective com pressive non linearity of OHCs The two tones interact in the cochlea close to the characteristic place of f2 Thus DPOAEs can be applied as a probe for frequency specific assessment of cochlear dysfunction at the f2 place TEOAEs disappear at a hearing loss higher than approx 15 dB HL in case of a conductive hearing loss and approx 30 dB HL in case of a cochlear hearing loss DPOAEs can not be detected at a hearing loss higher than approx 25 dB HL in case of a conductive hearing loss and approx 50 dB HL in case of a cochlear hearing loss respectively Before each OAE measurement calibration of the ear probe is automatically done In cases where the sound probe is not inserted properly or sound probe ports are blocked a warning incomplete will appear Four different OAE modes are available DPOAE threshold patented method for getting frequency specific and quantitative information of cochlear function at a hearing loss of up to 50 dB HL Threshold estimation is automatically done by extrapolating DPOAE I O functions obtained at primary tone levels between 15 and 65 dB Test frequencies are 1 5 2 3 4 6 and 8 kHz At frequencies at which not more than three valid DPOAEs per test frequency are measurable no extrapo lation is done In this cases simple threshold estimation is automatically perfor med The lowest stimulus level at whic
80. rent compression of the primary tones at the f2 place Kummer et al 2000 DPOAE pressure I O functions plot the DPOAE pressure pdp instead of the DPOAE level Ldp as a function of the primary tone level L2 Due to the logarith mic dependency of the DPOAE level on the primary tone level there is a linear dependency between DPOAE pressure pdp and primary tone level L2 Boege and Janssen 2002 Thus DPOAE data can easily be fitted by linear regression analy sis The intersection point of the linear regression line with the L2 axis at pdp 0 Pa can then serve as an estimate of the stimulus level at the DPOAE threshold 1 e Ldpth Boege and Janssen 2002 Gorga et al 2003 Estimated threshold level Lap when plotted across frequency f provides a mea sure for estimating CA threshold at the f place DPOAE slope calculated from DPOAE level I O functions e g between stimu lus levels L2 of 40 and 60 dB SPL indicates CA compression When plotted across frequency a slope profile can be established In ears with cochlear hea ring loss the slope s of the DPOAE level I O function increases with increasing hearing loss indicating loss of CA compression Janssen et al 1998 Kummer et al 1998 Muller and Janssen 2004 Neely et al 2003 There are some limitations when using DPOAE measures for assessing peripheral sound processing First electric microphone noise physiological noise breathing blood flow and external acoustic noise
81. roduct otoacoustic emissions in human new borns and adults I Frequency effects J Acoust Soc Am 103 981 91 LASKY R E 1998b Distortion product otoacoustic emissions in human new borns and adults II Level effects J Acoust Soc Am 103 992 1000 LIBERMAN M C amp DODDS L W 1984 Single neuron labeling and chronic cochlear pathology III Stereocilia damage and alterations of threshold tuning curves Hear Res 16 55 74 LONG G R amp TUBIS A 1988 Modification of spontaneous and evoked otoacoustic emissions and associated psychoacoustic microstructure by aspirin consumption J Acoust Soc Am 84 1343 53 LONSBURY MARTIN B L amp MARTIN G K 2001 Evoked Otoacoustic Emissions as Objective Screeners for Ototoxicity Semin Hear 22 377 392 MARGOLIS R H 2002 Influence of middle ear disease on otoacoustic emis sions In ROBINETTE M S amp GLATTKE T J eds Otoacoustic emissions clinical applications 2 ed ed New York Thieme MAUERMANN M amp KOLLMEIER B 2004 Distortion product otoacoustic emission DPOAE input output functions and the influence of the second DPOAE source J Acoust Soc Am 116 2199 212 MCFADDEN D amp PASANEN E G 1994 Otoacoustic emissions and quinine sulfate J Acoust Soc Am 95 3460 74 83 11 References 84 MCFADDEN D amp PLATTSMIER H S 1984 Aspirin abolishes spontaneous oto acoustic emissions J Acoust Soc Am 76 443 8 MILLS D M
82. rom 5 ms to 13 ms Valid response the statistical test criterion was reached Incomplete test the test criterion was not reached No Response the test criterion was not reached TEOAE diagnostic mode result AE LILE E RRS Bee Fo l m gt Stability 100 15 dB SNR 15 06 TEOAE 1 3 3 586 63 1 1 5 SNR criteria gt 6 gt 6 gt 6 gt 3 Overall criterion 3 5 11 2 Valid response Artefact 0 Stability 100 9 dB 6 1 SNR 4 kHz gt 3 dB 5 Upper Screen shows five TEOAE bands from 1 to 4 kHz the green response indicates that the selected criteria 3 or 6 or 10 dB has been reached The criteria can be selected press in the footer to adjust the settings By touching the upper screen the measurement results toggles inbetween graphic and table display Lower Screen shows statistical signals A B in a time window from 5 ms to 13 ms Result Valid response the statistical test criterion was reached Incomplete test the test criterion was not reached No Response the test criterion was not reached OAE How to use 31 5 SUN How to use SUN is a novel self controlled speech test designed for screening adults for hea ring disability using a set of intervocalic consonants VCVs The test is designed such that it 1s self convincing fast and of low cognitive load To fulfil these crite rions the SUN test is specifically desi
83. signal allows for automatic evaluation of OAE signals To minimize the influence of unwanted external signals algorithms for noise reduction and artefact rejection are applied In addition the noise floor level is reduced by time domain averaging of the recor ded signal TEOAE response sees almost the whole cochlea whereas the DPOAE response reflects only a limited region of the cochlea Therefore TEOAE Ss give a rapid overview of cochlear function whereas DPOAEs pro vide more quantitative information about sound processing at distinct cochlear places TEOAE DPOAE recording The noise floor level is usually higher at low frequencies due to microphone pro perties and low frequency body sounds such as breathing Artefact rejection can be performed by elimination of high noise level buffers sensitive to e g brea thing swallowing or head movements of the subject Furthermore when recor ding TEOAEs stimulus artefacts may generate signals being in phase in two ave raging buffers resulting in a pseudo response of high reproducibility By means of windowing functions the stimulus artefact can be excluded so that the reproduc1 bility of the overall signal is restricted to the signal section of interest Kemp et al 1990a Kemp et al 1990b It should be emphasized that since the stimulus artefact always appears in the early recording period the high frequency TEOAE components get lost as a result of the windowing procedure L
84. t on ABRs proper measuring conditions are essential Proper measuring con ditions are present 1f ABRs are measurable down to 10 dB nHL in a young normally hearing subject Intended clinical applications of ABRs are as follows Topological diagnostics assessment of peripheral and central sound processing on the auditory pathway up to the brainstem along with other audiological tests Identification of neural disorders eight nerve and low brainstem lesions on the audi tory pathway Non frequency specific determination of hearing loss within mid frequency region when using clicks Determination of hearing loss within different frequency regions when using low mid and high frequency chirp stimul1 In the following the use of ABR test is described in detail Corresponding button names and icons are as follows ABR ABR A Settings Enter F Play T Pause Skip gt Left right q Back IMA IM V Print w Info uu III Set 38 Preparation of the patient to be tested 6 1 Preparation of the patient to be tested Advise the subject to lay as comfortable as possible to avoid muscle activity Clean the skin where the electrodes will be placed Place electrodes Fig la Screen pictogram Fig 1b Cable pictogram There are several possibilities to place the electrodes The position of the electrodes affects waveform morphology and latency Best elec trode position for yielding maximum wave amplitudes is vertex
85. te steepens when the auditory threshold is elevated Jans sen et al 1998 Kummer et al 1998 Boege and Janssen 2002 Gorga et al 2003 Neely et al 2003 and differs significantly between hearing loss classes their width being 10 dB Janssen et al 2005b The slope of DPOAE I O functi ons is reported to be related to the slope of the loudness functions Neely et al 2003 Muller and Janssen 2004 Thus the slope of DPOAE I O functions is sug gested to allow a quantitative assessment of CA compression and hence provide an objective recruitment test Especially for hearing aid adjustment in children a quantitative evaluation of the hearing loss and recruitment is necessary With the help of the DPOAE audiogram and the DPOAE growth characteristic quantities of the cochlear impaired ear and hence additional parameters for a non cooperative hearing aid adjustment can be provided Muller and Janssen 2004 OAE measures are stable through time in any particular individual and hence are capable of monitoring recovery from OHC impairment Therapeutic drugs such as antibiotic e g aminoglycosides and anti tumor chemotherapeutic e g cispla tin agents are reported to induce an irreversible hearing loss that typically affects the highest frequencies first with hearing loss systematically progressing to the lower frequencies e g Kopelman et al 1988 Fausti et al 1994 Berg et al 1999 Stavroulaki et al 2001 Early detection of ot
86. test criterion Cochlear Status Cochlear Status 2 152 3 4 6 kHz R 21523 4 6 ete BOO gt invalid DPOAE test criterion 35 ee ae ee Ge 45 eT eee 5 YY O 5 DOvVvV Y r a ee ee e gt test criterion was skipped dB gt back to main menu gt back to test results TEOAE TEOAE Quick Mode or Diagnostic mode gt Select TEOAE Quick Diagnostic on the screen then select the ear side Ear Volume calibration gt The ear probe will first perform a ear volume calibration 28 OAE How to use If the probe is not placed properly in the ear canal the message incomplete will appear on the display In this case please correct the position of the probe Test Progress gt The progression of the test can be viewed on the display Display during measurement 10 25 TEOAE E AAA Stimulus stability preferably gt 80 Artifact preferably lt 20 Measuring time will depend on the test conditions noise and stability of the probe Progress IA Noise MA a 29 4 OAE How to use Artefact 0 30 i PAT a UND NS UNS Artefact 9 6 3 TEOAE Quick Test Result 0 Stability 100 5 13ms 0 i 1628 TEOAE SM tgp TEOAE A 0 Stability 100 Artefact 1 Stability 100 green and noise floor yellow over frequency range Artefact Upper Screen indicates OAE Signal Response Lower Screen shows statistical signals A B ina time window f
87. ther latencies recording parameters or quality data The footer shows now different buttons Back I II V print and info Print will print the results to the label printer Back leads to previous screen Info will show the online help I HI V enters the edit mode where you can mark peaks In the peak settings mode you may mark wave peaks in each response manually The active response can be selected by pressing the buttons to the left of each response 11 V selects the marker to be modified indicated the red point on top of the marker Set makes a peak marker permanent so that it will be stored with the test The marker will turn green to indicate this Left right moves the selected marker to set the latency of the corre sponding wave You may also set the marker by pressing on the desi red latency position Please note that order of the markers is always preserved with a minimum distance of 0 5 ms Back leaves the screen without saving new peak positions 45 6 ABR How to use Enter confirms the changes and goes back to the regular ABR result display When opening a result from result view you have the same editing options as described above after a measurement 6 3 ABR case examples 1 Normally hearing subject Click evoked ABRs in a normally hearing subject at 50 40 30 20 and 10 dB nHL stimulus levels ABRs are measur
88. ty best when recor ded at close to threshold stimulus levels Janssen et al 1998 Kummer et al 1998 Dorn et al 2001 DPOAE grams when recorded with narrow frequency spacing of f2 DPOAE fine structure may give information about the fine struc ture of the behavioral pure tone threshold However due to the superposition of the second DPOAE source He and Schmiedt 1993 He and Schmiedt 1996 He and Schmiedt 1997 Shera and Guinan 1999 the correlation between the two measures is not clear In normal hearing normal CA DPOAE grams are close to each other at high and more separated at low stimulus levels reflecting cochlear non linear sound processing In cochlear hearing loss ears impaired CA DPOAE grams are more separated even at high stimulus levels revealing loss of CA compression Janssen et al 1998 Kummer et al 1998 Neely et al 2003 DPOAE level I O functions plot the DPOAE level Ldp as a function of prima ry tone level L2 for a selected f2 and thus reflect CA dynamics at the f2 place in the cochlea Dorn et al 2001 In normal hearing in response to low level sti muli DPOAE level I O functions exhibit steep slopes while at high stimulus Types of OAEs levels slopes decrease thus mirroring the strong amplification at low and decrea sing amplification saturation at moderate sound levels However this is only true when a stimulus setting e g the scissor paradigm 1s used which accounts for the diffe
89. uch that the child was instructed that healthy animals will make sounds and sick animals are not able to The test procedure progress was visualized by a shelf from which the current test animal was selected The test was controlled by the child itself via touch screen This includes sound presentation as well as input if the sound was heard healthy animal or not sick animal The examiner super vised the measurement and assisted the child with the entry when indicated The examiner could also intervene in the measurement procedure at any time or do a retest at any frequency whenever necessary Additionally hearing threshold estimation by means of DPOAE I O functions see Relation between DPOAEs and behavioural pure tone thresholds p 69 were per formed in 36 children from the collective DPOAE I O functions were recorded at 53 7 MAGIC Description of Methods 54 frequencies f2 1 1 5 2 3 4 and 6 kHz with primary tone levels L2 in the range from 10 to 65 dB SPL and threshold were estimated by linear regression analysis Primary tone levels L1 and L2 were set according to the scissors para digm The frequency ratio f2 fl was 1 2 For comparison play audiometry pure tone thresholds were determined at the cor responding frequencies There was a highly significant p lt 0 001 correlation between image based MAGIC and play audiometry PTA thresholds The correlation coefficient r n 1247 was 0 73 The histogram o
90. ule by pressing ABR Select one of the presets by pressing the appropriate button By pressing Right or Left the test ear is selected and the test starts q P Alternatively the selected preset can be edited by pressing the settings button There are 4 settings pages Each has to be confirmed with enter in order to store the set tings magniture dB Perform measurements 13 30 ABR eL Stimulus Click Chirp Condensation Rarefaction Alternating W Jitter Y Masking noise C Auto Proceed C Auto Stop 1 1 5 time ms Fig 2a Time domain 1000 2000 30 00 4000 5000 600 frequency Hz Fig 2a Frequency domain 0 7000 9000 Select stimulus type Click or Chirp Both clicks and chirps are broad band stimuli Broad band stimuli are used to stimulate as many as possible sensory cells along the cochlea for getting highest neural activity on the nerve fibers The band width of a click see frequency domain Fig 2b blue line depends on stimu lus duration see time domain Fig 2a blue line The shorter the click the higher is the band width and with that the synchrony of neural activity on the auditory pathway However synchrony is decreased in the more apical regions of the cochlea in accordance with the decrease of the travelling wave velocity In contrast to the click the chirp is a long lasting stimulus which starts with low and
91. ween earphone and ear may give rise to falsely poor hearing threshold levels particularly at the highest frequencies When using insert sound probes the probes must be placed such that there is no leakage between ear tip and outer ear canal Ear probe ports must not be blocked with ear canal wax Tests have to be performed in an acoustic shielded booth or in a separate quite room Sentiero must not be used in cases of external otitis outer ear canal infec tion or in cases where the outer ear canal is occluded with cerumen ear wax Therefore otoscopy is advised before measurement especially before sound probe insertion 2 MAGIC How to use Play audiometry is a well established method in pediatric audiology However the test procedure in which the child must be continuously observant is exhausting and the task usually placing a peg in a pegboard is varied only little In contrast image based and self paced test procedures can considerably enhance the child s attentiveness MAGIC Multiple choice auditory graphic interactive check is a new tool with which pure tone thresholds can be determined in a playful way Using a self con trolled measuring procedure the child s attentiveness 1s significantly enhanced Intended use of MAGIC is to determine pure tone thresholds in young children preschool and school children MAGIC can be performed at frequencies between 0 250 kHz and 8 kHz Different animals represented different

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