阻塞性睡眠呼吸暂停低通气综合征患者的早期听觉损害评估手段探讨

目的探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者的早期听觉损害评估方法。方法对31例(62耳)OSAHS患者和20例(40耳)对照组,分别检测常频(0.125～8 kHz)纯音气骨导和扩展高频(8～16 kHz)气导听阈、瞬态诱发性耳声发射(TEOAE)及畸变产物耳声发射(DPOAE)。结果①常频纯音听阈两组间无显著差异,而扩展高频听阈OSAHS组明显高于对照组(t=3.045～3.779,P=0.000～0.003);②TEOAE检出率OSAHS组为37.1%,而对照组为92.5%,组间差异显著,χ2=30.82,P=0.000;③在各个频率点DPOAE检出率和振幅,OSAHS组明显低于对照组(检出率χ2=22.94～34.31,P=0.000～0.000;振幅t=-2.740～-9.980,P=0.000～0.008)。结论对于OSAHS患者建议用耳声发射、扩展高频测听进行早期听觉损害评估。     

Age dependence of otoacoustic emissions: the loss of amplitude is primarily caused by age-related hearing loss and not by aging alone

The amplitude of otoacoustic emissions (OAE) is known to decrease with increasing age, but it is still unclear whether this is due to aging alone or to age-related hearing loss. This study describes the exploration of a large database (5,142 patients from 0.4 to 89.8 years) collected in a routine clinical testing. Reliable pure tone audiograms, transitory evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) recordings were available from 5,424 ears without conductive loss, acute sudden deafness or retrocochlear disorder. From this database, group 1 with behavioral thresholds of 10 dB HL or better at all frequencies from 1 to 4 kHz and group 2 with age-accordant thresholds after ISO 7029 were formed. In both groups, the OAE amplitude decreased with increasing age, but in group 1, the effect was significant only for DPOAE recorded at 3 and 4 kHz. In group 2, the loss of amplitude was steeper and highly significant for TEOAE as well as DPOAE at all frequencies, but most pronounced at high frequencies. These findings support the hypothesis that the reduction of OAE amplitude with increasing age is primarily caused by age-linked hearing loss and not by aging alone.     

A longitudinal study of changes in evoked otoacoustic emissions and pure-tone thresholds as measured in a hearing conservation program

Non-linear transient-evoked otoacoustic emissions (TEOAEs) at 74dB pSPL, distortion-product otoacoustic emissions (DPOAEs) at 65/45dB SPL and pure-tone audiometry were used to detect noise-induced, inner car changes in a longitudinal study. Repeated-measures ANOVAs were made on the Noise (n=69) and Quiet (n=42) groups. The Noise group's hearing thresholds increased by 1.2 dB and DPOAE amplitude decreased by -0.9 dB. For both groups, TEOAE amplitude decreased by approximately -0.6 dB. Eight of 12 ears with permanent threshold shift (PTS) and 10 of 13 ears with temporary threshold shift (TTS) showed TEOAE decrements or low baseline TEOAE amplitudes. Fewer TTS and PTS ears also showed DPOAE decrements, and there was never a DPOAE decrement without a corresponding TEOAE decrement or low TEOAE baseline. Some TTS ears showed permanent emission decrements. Although otoacoustic emissions show promise in detecting noise-induced inner ear changes, it is premature to use them in hearing conservation programs.     

A longitudinal study of changes in evoked otoacoustic emissions and pure-tone thresholds as measured in a hearing conservation program

Non-linear transient-evoked otoacoustic emissions (TEOAEs) at 74 dB pSPL, distortion-product otoacoustic emissions (DPOAEs) at 65/45 dB SPL and pure-tone audiometry were used to detect noise-induced, inner ear changes in a longitudinal study. Repeated-measures ANOVAs were made on the Noise (n=69) and Quiet (n=42) groups. The Noise group's hearing thresholds increased by 1.2 dB and DPOAE amplitude decreased by ?0.9 dB. For both groups, TEOAE amplitude decreased by approximately ?0.6 dB. Eight of 12 ears with permanent threshold shift (PTS) and 10 of 13 ears with temporary threshold shift (TTS) showed TEOAE decrements or low baseline TEOAE amplitudes. Fewer TTS and PTS ears also showed DPOAE decrements, and there was never a DPOAE decrement without a corresponding TEOAE decrement or low TEOAE baseline. Some TTS ears showed permanent emission decrements. Although otoacoustic emissions show promise in detecting noise-induced inner ear changes, it is premature to use them in hearing conservation programs.     

Effect of ageing on otoacoustic emissions and efferent suppression in humans.

Transiently evoked otoacoustic emissions (TEOAEs) without and with contralateral acoustical stimulation, were recorded on 52 subjects ranging from 20 to 78 years. Subject selection was based on the hearing levels from 0.5 to 4 kHz being better than 25 dB HL, normal tympanograms and stapedial reflexes, presence of TEOAEs in at least one ear and no history of otological disease, noise exposure, ototoxic drugs, metabolic disease associated with hearing loss or a family history of hearing loss. The ear with better audiological thresholds was selected as the test ear. If there was no difference between the ears, the ear with stronger TEOAEs was selected. Subjects were divided into five age groups: 20-34 years (n=12, mean age 23.7), 35-44 (n=11, mean age 39.7), 45-54 (n=8, mean age 48.1), 55-64 (n=10, mean age 60), 65-78 (n=11, mean age 71). TEOAEs were never absent in the first two groups, but they were absent in two ears in the 45-54 group, and in one ear of the 55-64 and 65-78 groups. Mean TEOAE amplitude decreased with age, but the differences between the five groups were not significant. Contralateral white noise suppressed emission amplitude, but the amount of suppression was not significantly different between the five groups. A linear regression analysis showed a significant correlation between age and hearing levels, and a negative correlation between age and TEOAE amplitude. In addition, a significant negative correlation between hearing threshold and TEOAE amplitude was evident. No effect of age on the amplitude of the efferent suppression was found.     

听觉神经病

目的　探讨听觉神经病的临床特点、听力学及电生理特征。方法　总结了 17例听觉神经病患者的病史、纯音及语言听力、镫骨肌反射、听性脑干反应 (auditorybrainstemresponse ,ABR)、耳蜗电图、鼓岬电刺激试验、耳声发射及对侧声抑制试验的特点。结果　该病多在青春期后起病 ,女性较多发 ,表现为渐进性双耳对称性听力下降 ,纯音听力以低频损失为主 ,语言接受阈升高 ,分辨率下降 ,镫骨肌反射及ABR引不出或阈值明显升高与纯音听力不成比例 ,耳蜗微音器电位正常 ,听神经动作电位引不出 ,耳声发射波幅高、时程长且不为对侧声刺激所抑制。结论　听觉神经病的诊断应在除外各种已知原因的感音神经性聋后 ,根据其纯音听力与客观测听的不一致及电生理学上的耳蜗活动与中枢系统反应分离的特征作出 ,对该病的认识尚需进一步深入。     

纯音听阈正常的耳闷患者诱发性耳声发射分析

目的:对纯音听阈正常的耳闷患者进行诱发性耳声发射分析,以早期发现这些患者的耳蜗损害.方法:采用丹麦Madsen公司Capella耳声发射仪对纯音听阈正常的耳闷患者43例(72耳,耳闷组)及正常人30例(60耳,对照组)分别进行TEOAE及DPOAE检测,记录和分析各频率DPOAE的检出率、幅值,TEOAE的通过率、反应波信噪比、波形重复性及各频带反应波信噪比和重复性.结果:①DPOAE检出率仅在0.50、0.75 kHz两频点上耳闷组明显低于对照组(P＜0.05),其余各频率点差异均无统计学意义(P＞0.05);②TEOAE通过率对照组为100%,耳闷组为90.28%,2组比较差异有统计学意义(X2=6.16,P＜0.05);③与对照组相比,纯音听阈正常的耳闷患者各频率DPOAE的幅值、TEOAE的反应波信噪比、波形重复性及各频带反应波信噪比和重复性均降低,差异有统计学意义(P＜0.05或P＜0.01).结论:部分纯音听阈正常的耳闷患者已存在耳蜗外毛细胞的损害,利用诱发性耳声发射的方法可在其听力损失出现之前早期发现此类病变.     

Transient-evoked otoacoustic emissions in a representative population sample aged 18 to 25 years

Transient-evoked otoacoustic emissions (TEOAEs) were obtained from 688 ears of a group of 345 young adults aged 18 to 25 years, using the Otodynamics ILO88 in the standard, non-linear mode. Normative data for TEOAEs obtained from 186 otologically normal (ON) ears are presented. In 5 ON ears, there was no recordable response, despite hearing threshold levels better than 20 dB. The main factors affecting the TEOAE level were (1) gender, where females had larger responses on average than males; (2) tympanometric measures, where ears with entirely normal tympanometric measures had larger responses than those with minor tympanometric abnormalities; (3) click stimulus intensity measured in the ear canal, which correlated positively with TEOAE level; and (4) hearing threshold level at 0.5 kHz, which correlated negatively with amplitude. There was also a small effect of social noise exposure in the 2-kHz region of the TEOAE, where the response was lower in those subjects exposed to significant social noise.     

Transient-Evoked Otoacoustic Emissions in a Representative Population Sample Aged 18 to 25 Years: Emisiones otoacüAsticas evocadas por transitorios en una muestra representativa de población con edades entre 18 y 25 años

Transient-evoked otoacoustic emissions (TEOAEs) were obtained from 688 ears of a group of 345 young adults aged 18 to 25 years, using the Otodynamics ILO88 in the standard, non-linear mode. Normative data for TEOAEs obtained from 186 otologically normal (ON) ears are presented. In 5 ON ears, there was no recordable response, despite hearing threshold levels better than 20 dB. The main factors affecting the TEOAE level were (1) gender, where females had larger responses on average than males; (2) tym-panometric measures, where ears with entirely normal tympanometric measures had larger responses than those with minor tympanometric abnormalities; (3) click stimulus intensity measured in the ear canal, which correlated positively with TEOAE level; and (4) hearing threshold level at 0.5 kHz, which correlated negatively with amplitude. There was also a small effect of social noise exposure in the 2-kHz region of the TEOAE, where the response was lower in those subjects exposed to significant social noise.     

瞬态诱发耳声发射检测职业性听力损伤的可行性研究

目的 :探讨瞬态诱发耳声发射 (TEOAE)检测职业性听力损伤的可行性及临床应用价值。方法 :选择 90例 (180耳 )噪声暴露工人为实验总组 ,按噪声暴露时间长短又分为 1、2、3组 ;另选 11例 (2 2耳 )正常听力青年人作为对照组 ,行纯音听阈和TEOAE测试。结果 :各实验组纯音听阈值明显高于对照组 ,TEOAE总重复率、幅值和信噪比及各频段重复率、幅值和信噪比明显低于对照组 (P <0 .0 5或P <0 .0 1)。实验 1、2、3组间比较 ,随着噪声接触时间的增加 ,各频率点纯音听阈提高 ,TEOAE总重复率、幅值和信噪比及各频段重复率、幅值和信噪比变小 ,在 2 .5 0～ 3.5 0kHz和 3.5 0～ 4 .5 0kHz频段最明显。结论 :用TEOAE检测职业性听力损伤是可行的 ,有临床应用价值 ,最敏感频段为 2 .5 0～ 3.5 0kHz和 3.5 0～ 4 .5 0kHz频段。     

听觉神经病

目的 探讨听觉神经病的临床特点、听力学及电生理特征。方法 总结了１７例听觉神经病患者的病史、纯音及语言听力、镫骨肌反射、听性脑干反应（ａｕｄｉｔｏｒｙ ｂｒａｉｎｓｔｅｍ ｒｅｓｐｏｎｓｅ，ＡＢＲ）、耳蜗电图、鼓岬电刺激试验、耳声发射及对侧声抑制试验的特点。结果 该病多在青春期后起病，女性较多发，表现为是性双耳对称性听力下降，纯音听力以低频损失为主，语言接受阈升高，分辨率下降，镫骨肌反射及ＡＢＲ引     

Spontaneous otoacoustic emissions and sensori-neural hearing loss.

This study sought to clarify the clinical relevance of spontaneous otoacoustic emissions (SOAEs) and to define the hearing loss level (and frequency) at which absence of SOAE is found. Findings from 126 ears of patients with sensori-neural hearing loss showed an incidence of SOAEs in 18.25% of the cases (23 out of 126 ears). SOAEs were never found when hearing loss at 1,000 Hz exceeded 10 dB. The presence of SOAE seems to indicate a good cochlear functioning at least in the mid-frequencies. Although the incidence of SOAEs is markedly lower than that of evoked otoacoustic emissions (EOAEs), SOAE recording is shown to be a good test, rapid, non-invasive for audiological screening, the presence of SOAE confirming a hearing threshold of less than 10 dB at 1,000 Hz, the absence of SOAE being inconclusive.     

TEOAE-based estimation of the auditory threshold in the mid-octave frequencies

The purpose of this study was to estimate the hearing levels, at the mid-frequencies, of 233 ears with sensorineural hearing loss by classifying the corresponding transiently evoked otoacoustic emissions (TEOAE) recordings into three threshold groups. A classification algorithm was based upon a discriminant analysis of fast Fourier transform (FFT) data, evoked by non-linear click stimuli of 80 (+/-2) dB SPL per ear. To validate the efficiency of the proposed methodology TEOAE recordings were initially grouped by mean hearing level values of the 1 kHz and 2 kHz octaves into three threshold ranges according to two strategy schemes: in the first, TEOAE data were assigned into 10-19 dB HL, 20-39 dB HL or > or = 40 dB HL groups. In the second, TEOAE data were assigned into 10-29 > dB H >, 30-39 dB HL or > or = 40 dB HL groups. The most accurate prediction estimates were obtained from the second strategy scheme with a 90.9% accuracy in the 10-29 dB HL group, 82% in the 30-39 dB HL group and 71.4% in the > or = 40 dB HL group.     

Effect of Ageing on Otoacoustic Emissions and Efferent Suppression in Humans: Efectos de la edad en las emisiones otoacústicas y (EN LA) supresión eferente en humanos

Transiently evoked otoacoustic emissions (TEOAEs) without and with contralateral acoustical stimulation, were recorded on 52 subjects ranging from 20 to 78 years. Subject selection was based on the hearing levels from 0.5 to 4 kHz being better than 25 dB HL, normal tympanograms and stapedial reflexes, presence of TEOAEs in at least one ear and no history of otological disease, noise exposure, ototoxic drugs, metabolic disease associated with hearing loss or a family history of hearing loss. The ear with better audiological thresholds was selected as the test ear. If there was no difference between the ears, the ear with stronger TEOAEs was selected. Subjects were divided into five age groups: 20–34 years (n=12, mean age 23.7). 35–44 (n=11, mean age 39.7), 45–54 (n=8, mean age 48.1), 55–64 (n=10, mean age 60), 65–78 (n=11, mean age 71). TEOAEs were never absent in the first two groups, but they were absent in two ears in the 45–54 group, and in one ear of the 55–64 and 65–78 groups. Mean TEOAE amplitude decreased with age, but the differences between the five groups were not significant. Contralateral white noise suppressed emission amplitude, but the amount of suppression was not significantly different between the five groups. A linear regression analysis showed a significant correlation between age and hearing levels, and a negative correlation between age and TEOAE amplitude. In addition, a significant negative correlation between hearing threshold and TEOAE amplitude was evident. No effect of age on the amplitude of the efferent suppression was found.     

Subjective audiological tests and transient evoked otoacoustic emissions in patients with rheumatoid arthritis: analysis of the factors affecting hearing levels

We investigated hearing functions in patients with rheumatoid arthritis (RA) using audiological tests and transient evoked otoacoustic emissions (TEOAEs). The study group consisted of 20 adult patients with RA (7 males, 13 females); 20 adult healthy subjects without RA (7 males, 13 females) were recruited as controls. All patients were evaluated by pure tone audiometry, high frequency audiometry, tympanometry and TEOAEs. There were no statistical differences between the study and control groups with respect to the pure tone and high frequency audiometries. TEOAE results of 1.0–2.0 kHz % and of 1.5 and 3.0 kHz amplitude values were significantly lower, and ipsilateral stapes reflex threshold value at 1.0 kHz was significantly higher in the study group when compared to respective values in the control group. In elderly patients and those with longer disease duration, RA nodules and higher methotrexate cumulative doses, hearing thresholds increased and TEOAE values decreased. In active stage of the disease, hearing thresholds diminished and in higher Brinkman Index values, TEOAE values decreased. Compliance values decreased in patients with higher Ritchie Articular Index, C-reactive protein, erythrocyte sedimentation rate and platelet counts, and longer disease duration. Sensorineural hearing loss is generally observed in patients with RA, and this condition may be detected by TEOAEs in an early period of the disease. Inflammation during the active stage of the disease and the subsequent fibrosis may cause conductive hearing loss of varying degrees. In those patients detected as having initiation of TEOAE decrease, vasodilator treatment and antioxidant drugs may be useful in protecting the inner ear.     

Diplacusis, hearing threshold and otoacoustic emissions in an episode of sudden, unilateral cochlear hearing loss

Limited data are available on the relationship between diplacusis and otoacoustic emissions and sudden hearing threshold changes, and the detail of the mechanism underlying diplacusis is not well understood. Data are presented here from an intensively studied single episode of sudden, non-conductive, mild hearing loss with associated binaural diplacusis, probably due to a viral infection. Treatment with steroids was administered for 1 week. This paper examines the relationships between the hearing loss, diplacusis and otoacoustic emissions during recovery on a day-by-day basis. The hearing thresholds were elevated by up to 20 dB at 4kHz and upwards, and there was an interaural pitch difference up to 12% at 4 and 8 kHz. There was also a frequency-specific change in transient evoked otoacoustic emission (TEOAE) and distortion-product otoacoustic emission (DPOAE) level. DPOAE level was reduced by up to 20 dB. with the greatest change seen when a stimulus with a wide stimulus frequency ratio was used. Frequency shifts in the 2f2-fi DPOAE fine structure corresponded to changes in the diplacusis. Complete recovery to previous levels was observed for TEOAE, DPOAE and hearing threshold. The diplacusis recovered to within normal limits after 4 weeks. The frequency shift seen in the DPOAE fine structure did not quite resolve, suggesting a very slight permanent change. The time-courses of TEOAE. diplacusis and hearing threshold were significantly different: most notably, the hearing threshold was stable over a period when the diplacusis deteriorated. This suggests that the cochlear mechanisms involved in diplacusis, hearing threshold and OAE may not be identical.     

Otoacoustic Emissions in Smoking and Nonsmoking Young Adults

Objectives

The present study investigates the usefulness of transiently evoked otoacoustic emissions (TEOAEs) and distortion product OAEs (DPOAEs) in detecting small changes in the hearing of young smoking adults.

Methods

Otoacoustic emissions were acquired from the ears of 48 young adults (age, 20 to 27 years). The dataset was divided into two groups, smoking (24 persons/48 ears) and nonsmoking (24 persons/48 ears). The level of smoking was relatively small in comparison to previous studies, an average of 3.8 years and 8.7 cigarettes per day. In each ear three OAE measurements were made: TEOAEs, DPOAEs, and spontaneous OAEs (SOAEs). Pure tone audiometry and tympanometry were also conducted. Audiometric thresholds did not differ significantly between the datasets. Half-octave-band values of OAE signal to noise ratios and response levels were used to assess statistical differences.

Results

Averaged data initially revealed that differences between the two study groups occurred only for TEOAEs at 1 kHz. However when the datasets were divided into ears with and without SOAEs more differences became apparent, both for TEOAEs and DPOAEs. In ears that exhibited SOAEs, both smokers and nonsmokers, there were no statistically significant differences between evoked OAEs; however in all ears without SOAEs, evoked OAEs were higher in the ears of nonsmokers, by as much as 5 dB. These differences were most prominent in the 1-2 kHz range.

Conclusion

A general decrease in OAE levels was found in the group of smokers. However, in ears which exhibited SOAEs, there was no difference between the evoked OAEs of smokers and nonsmokers. We conclude that smoking had not yet measurably affected the ears of those with acute hearing (i.e., those who exhibit SOAEs). However, in ears without SOAEs, smokers exhibited smaller evoked OAE amplitudes than nonsmokers, even though their audiometric thresholds were within the norm.     

Otoacoustic emissions and tympanometry in a general adult population in Sweden

The present study concerns a general adult population in Sweden, not exposed to hazardous occupational noise. Tympanometry and spontaneous (SOAE), transient evoked (TEOAE) and distortion-product (DPOAE) otoacoustic emissions were investigated in 493 randomly selected men and women aged from 20 to 79 years. Effects of gender, age, ear side and middle ear state were determined, with and without adjusting for hearing threshold level. No statistically significant effects on middle ear pressure or compliance were present. For TEOAEs and DPOAEs, the effect of gender and age was statistically significant (p < 0.01), with larger signal levels for female subjects and young subjects, even after adjusting for hearing threshold level. No effect of middle ear pressure on otoacoustic emissions was present, but high middle ear compliance was associated with low emission levels (p < 0.01). Reference data for middle ear compliance and pressure and prevalence data on SOAEs, TEOAEs and DPOAEs for male and female subjects in different age groups were determined. Mean signal levels of TEOAEs and DPOAEs are presented.     

Diplacusis,hearing threshold and otoacoustic emissions in an episode of sudden,unilateral cochlear hearing loss

Limited data are available on the relationship between diplacusis and otoacoustic emissions and sudden hearing threshold changes, and the detail of the mechanism underlying diplacusis is not well understood. Data are presented here from an intensively studied single episode of sudden, non-conductive, mild hearing loss with associated binaural diplacusis, probably due to a viral infection. Treatment with steroids was administered for 1 week. This paper examines the relationships between the hearing loss, diplacusis and oto-acoustic emissions during recovery on a day-by-day basis. The hearing thresholds were elevated by up to 20 dB at 4 kHz and upwards, and there was an interaural pitch difference up to 12% at 4 and 8 kHz. There was also a frequency-specific change in transient evoked otoacoustic emission ( TEOAE) and distortion-product otoacoustic emission (DPOAE) level. DPOAE level was reduced by up to 20 dB, with the greatest change seen when a stimulus with a wide stimulus frequency ratio was used. Frequency shifts in the 2f2 – f1 DPOAE fine structure corresponded to changes in the diplacusis. Complete recovery to previous levels was observed for TEOAE, DPOAE and hearing threshold. The diplacusis recovered to within normal limits after 4 weeks. The frequency shift seen in the DPOAE fine structure did not quite resolve, suggesting a very slight permanent change. The timecourses of TEOAE, diplacusis and hearing threshold were significantly different; most notably, the hearing threshold was stable over a period when the diplacusis deteriorated. This suggests that the cochlear mechanisms involved in diplacusis, hearing threshold and OAE may not be identical.     

Transient-evoked otoacoustic emissions in a group of professional singers who have normal pure-tone hearing thresholds

OBJECTIVES: The objective of this study was to determine whether transient-evoked otoacoustic emissions (TEOAEs) measured in a group of normal-hearing professional singers, who were frequently exposed to high-level sound during rehearsals and performances, differed from those measured in age- and gender-matched normal-hearing non-singers, who were at minimal risk of hearing loss resulting from excessive sound exposure or other risk factors. DESIGN: Twenty-three normal-hearing singers (NH-Ss), 23 normal-hearing controls (NH-Cs), and 9 hearing-impaired singers (HI-Ss) were included. Pure-tone audiometry confirmed normal-hearing thresholds (>or=15 dB HL) at 0.5, 1.0, 2.0, 3.0, 4.0, 6.0, and 8.0 kHz in NH-Ss and NH-Cs, and confirmed mild, high frequency, sensorineural hearing loss in HI-Ss (HI-Ss were included only to estimate sensitivity and specificity values for preliminary pass or fail criteria that could be used to help identify NH-Ss at risk for music-induced hearing loss). TEOAEs were measured twice in all ears. TEOAE signal to noise ratio (S/N) and reproducibility were examined for the whole wave response, and for frequency bands centered at 1.0, 1.4, 2.0, 2.8, and 4.0 kHz. RESULTS: Moderate to high correlations were found between test and retest TEOAE responses for the three groups. However, absolute test-retest differences revealed standard deviations that were two to three times larger than those reported previously, with the majority of the variability occurring for the 1.0 kHz band. As such, only the best TEOAE response (B-TEOAE) from the two measurements in each ear was used in further analyses, with data from the 1.0 kHz band excluded. With one exception, within-group comparisons of B-TEOAE S/N and reproducibility across ears and gender revealed no statistically significant differences for either NH-Ss or NH-Cs. The only significant within-group difference was between left and right ears of NH-C females for S/Ns measured in the 2.0 kHz band, where median responses from right ears were found to be higher than left ears. Across-group comparisons of B-TEOAEs revealed lower median S/N and reproducibility values for NH-Ss compared with NH-Cs for the whole wave response and 1.4 kHz band. For the 2.0 kHz band, reproducibility was similar for the normal-hearing groups but median S/N was found to be lower for NH-Ss. No significant differences in S/N or reproducibility were found between normal-hearing groups for the 2.8 and 4.0 kHz bands. Using data from NH-Cs and HI-Ss to establish sensitivity and specificity values for various TEOAE pass or fail criteria, six preliminary criteria were identified as having sensitivity and specificity values >or=90%. When these criteria were applied to NH-Ss, the number of NH-S ears passing ranged from 57% to 76%, depending on the criteria used to judge the NH-S ears, which translates into 24% to 43% of ears failing. CONCLUSIONS: Although TEOAE responses were measurable in all singers with normal audiometric thresholds, responses were less robust than those of NH-Cs. The findings suggest that subtle cochlear dysfunction can be detected with TEOAE measurement in a subset of normal-hearing professional singers. Although preliminary, the study findings highlight the importance of pass or fail criterion choice on the number of ears that will be identified as "at risk" for music-induced hearing loss.