Seasonal effects on transient evoked otoacoustic emission screening outcomes in infants versus 6-year-old children

The purpose of this study was to compare transient evoked otoacoustic emission (TEOAE) screening outcomes (pass/fail) across the seasons (spring, autumn, and winter) between infants and schoolchildren. A total of 526 infants (275 boys, 251 girls) with a mean age of 2.0 months (SD = 0.38 months) and 975 schoolchildren (513 boys, 462 girls) with a mean age of 6.2 years (SD = 0.36 years) were screened using the ILO Otodynamics Quickscreen program. The same TEOAE pass/fail criterion was applied to the two groups. The results indicated a significant difference in pass rates between infants (91.2% of 1052 ears) and schoolchildren (86.0% of 1950 ears). A seasonal effect was found only for schoolchildren, with a significantly lower pass rate in winter than in spring or autumn. There was no difference in pass rates between spring and autumn. Implications for the seasonal effect on TEOAE screening outcomes for infants and schoolchildren are discussed.     

Noise suppression of transient-evoked otoacoustic emissions. II. Derived narrow-band contributions

Transient-evoked otoacoustic emissions (TEOAEs) were decomposed into cochlear place specific components using high-pass noise suppression. This was performed using high-pass filtered noise with cut-off frequencies between 0.7 and 5.6 kHz in 0.5-octave steps. Subtraction of the TEOAEs obtained in the presence of two high-pass noise suppressors with 0.5-octave difference in their cut-off frequencies, f(A) and f(B), should theoretically result in TEOAE components with frequencies between f(A) and f(B). The reconstructed wide-band emission power spectrum obtained by summing the narrow-band emission power spectra, was nearly identical to the power spectrum of the original wide-band emission. This suggests that no phase-cancellation occurs and that the individual narrow-band TEOAEs are uncorrelated, and thus that their generators are potentially independent. About 66% of the derived narrow-band emissions had spectral components that extended below the cut-off frequency of the lower high-pass noise filter. These tail components were interpreted as resulting from high-frequency side suppression of the high-pass noise on the click emission and potentially distortion product components from the TEOAE.     

瞬态耳声发射的主频对梅尼埃病的诊断价值

为探讨检测TEOAE的主频对诊断梅尼埃病的应用价值,本研究用ILO 88测试系统以click声为刺激信号,对正常耳和梅尼埃病耳作瞬态耳声发射(TEOAE)检测,观察其主频范围.发现正常耳的主频集中在1.2～l.6kHz之间,梅尼埃病主频集中在0.8～1.1kHz之间,正常耳的主频明显高于梅尼埃耳的主频.梅尼埃病人服用甘油后,TEOAE主频发生变化,由低频转为高频,未引出耳声发射耳,服用甘油后耳声反射引出.以上结果提示,检测TEOAE的主频对梅尼埃病的诊断有一定意义.     

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.     

Clinical applications of transiently evoked otoacoustic emissions in the pediatric population

Our objectives were 1) to determine whether transiently evoked otoacoustic emissions (TEOAEs) are affected by the status of the tympanic membrane (TM) and middle ear (ME) as determined by clinical examinations and tympanograms; 2) to determine the efficacy of TEOAEs in detecting hearing loss; and 3) to determine the relative effects of the ME status and hearing loss on TEOAEs. In a prospective observational study in a tertiary care children's hospital, 89 patients (169 ears; 9 ears eliminated from analyses) were examined by 2 attending pediatric otolaryngologists for otologic conditions and underwent audiologic evaluations including TEOAEs from August 1994 through May 1995. The main outcome measures were presence or absence of TEOAE whole reproducibility (WR) and reproducibility (R) at 2 kHz. Statistical analyses showed that of the 8 ME and TM conditions evaluated (normal, TM perforation, pressure equalization [PE] tube, TM retraction, tympanosclerosis, TM atrophy, ME effusion, surgery other than PE tube insertion), only the presence of ME effusion and normal examination findings had a significant effect on the results of WR and R at 2 kHz. Of the 6 different types of tympanograms evaluated (A, B, C, AD, As, B with large volume), type A, B, and C tympanograms had a significant effect on WR and types A and B had a significant effect on R at 2 kHz. Hearing losses > or = 25 dB hearing level (HL) at any of the 5 frequencies (0.25, 0.5, 1, 2, and 4 kHz) were well predicted by the absence of WR and R at 2 kHz. When clinical examination and impedance data were evaluated simultaneously with hearing status, hearing status had a greater effect on WR and R at 2 kHz. We conclude that type B and C tympanograms and the presence of ME effusion (which reflect abnormal ME status) have an adverse effect on TEOAEs. However, the presence of hearing loss is the most significant predictor of TEOAE results. The TEOAE WR and R at 2 kHz are effective in identifying patients with normal hearing and with hearing losses > or = 25 dB HL.     

Paediatric hearing screening in the community: a comparison of outcomes from transient evoked and distortion product otoacoustic emission measures

The present study aimed to compare TEOAE screening outcomes based on different pass/fail criteria and the outcomes from TEOAE and DPOAE measures in children. For the purpose of the study, the subjects were divided into two age groups: group 1 (n = 36; mean age 2.7 months, SD 1.2), and group 2 (n = 29; mean age 37.5 months, SD 16.3). Results indicated that the agreement of screening outcomes between pass/fail criteria for the TEOAE measure and between TEOAE and DPOAE measures was significantly lower for the younger group than for the older group. The greater variability in the younger age group could be partly attributed to the higher physiological noise produced by young infants. Irrespective of the pass/fail criteria used, the findings of the present study suggest that the OAE outcomes for children with weak OAEs or OAEs obscured by excessive noise were most variable.     

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。     

基层医院新生儿听力筛查方法与评定标准的建立

目的 :探讨新生儿听力筛查的最佳方法与相关标准。方法 :应用Cepella耳声发射仪对 12 77例(2 5 5 4耳 )新生儿作瞬态诱发耳声发射 (TEOAE)测试。以 4个频带中 3个频带信噪比≥ 3dB为通过标准。结果 :通过率为 89.4%,测试时间以产后 2d以上为佳。结论 :TEOAE是新生儿听力筛查的首选方法 ,频带信噪比≥ 3dB为最适当的筛查标准。     

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.     

背景噪声对新生儿瞬态诱发耳声发射的影响

目的 分析背景噪声对新生儿瞬态诱发耳声发射(TEOAE)的影响.方法 对122例通过听力筛查的新生儿(244耳,女62例,男60例)分别以短声刺激行TEOAE检测,用quick TEOAE模式,叠加次数大于100次.并以背景噪声分组,比较安静组与噪声组之间TEOAE差异.结果 ①新生儿TEOAE的背景噪声为(33.94...     

Optimal band pass filtering of transient evoked otoacoustic emissions in neonates

This paper investigated the performance of an optimal bandpass filtering technique to effectively identify click evoked otoacoustic emissions in neonates. The frequency response of the filter was optimized by maximizing the correlation coefficient between two replicate recordings (reproducibility). The optimal cut-off frequencies were also set by controlling the maximum energy loss after filtering to stop the crucial response contents being filtered along with the noise. As an additional constraint, the cut-off frequencies were forced to be outside the range of 1.6 to 4.2 kHz to avoid (in a response identification task) the spontaneous otoacoustic emissions from polarizing the cut-offs and thereby filtering fundamental frequency components, thus leading to an erroneous response classification. The best performance of the optimal filter in terms of increasing the post-filtering reproducibility was obtained when the procedure was applied to recordings whose reproducibility before filtering ranged between 60 and 80 per cent, i.e. for responses classified in most cases as partial pass.     

新生儿与成人瞬态诱发耳声发射差异的频谱特性分析

目的 比较新生儿与成人瞬态诱发耳声发射(TEOAE)的差异,并分析其频谱特性.方法 以短声刺激分别对120名通过听力筛查的新生儿(男58,女62)和32名平均纯音听阈(听力级)在20 dB以内的成年人(男15,女17)行TEOAE检测,对于测试结果 行频谱分析和半倍频程分析.结果 ①新生儿组TEOAE总强度(声压级,下同)为(15.18±4.39)dB,高于成人组的(9.51±4.12)dB,差异具有统计学意义(t=9.303,P<0.05).②新生儿的频带重复率、频带重复率非0比例、频带信噪比检出率及频带信噪比在第1频带(0.8 kHz)最低,在3.2 kHz最大;而成人在第5频带(4.0 kHz)处最低,在1.5 kHz最大.③新生儿与成人最大频带信噪比强度差为7.09 dB,二者出现的频率位置相差约1.7 kHz.④半倍频程分析显示新生儿TEOAE最大能量为(10.50±5.09)dB,在2828 Hz处,而成人为(2.84±5.33)dB,在1414 Hz处;二者最大反应在强度上相差7.66 dB,出现的频率位置相差1414 Hz.⑤成人1.5 kHz区的TEOAE信号最强,之后其信噪比随频带增高而降低,而新生儿信噪比却呈现随频带增高而增强的特征;从第1频带到第5频带,新生儿与成人TEOAE强度的差值随频带增高也逐渐增大.结论 成人TEOAE总强度低于新生儿.新生儿频带信噪比及半倍频程能量反应峰的分布频率及反应强度均高于成人.     

Linear and nonlinear transient evoked otoacoustic emissions in humans exposed to noise

Transient evoked otoacoustic emissions (TEOAEs) have been analyzed in a population of 134 ears, divided into three classes: (1) nonexposed ears in bilaterally normal hearing subjects, (2) audiometrically normal ears of subjects exposed to noise and affected by unilateral high-frequency (f>3 kHz) hearing loss in the contralateral ear, and (3) the contralateral impaired ears of the exposed subjects. The statistical distributions of global and spectral signal-to-noise ratio (SNR) were analyzed. TEOAEs were recorded both in the linear and nonlinear acquisition mode to evaluate the effectiveness of two standard averaging techniques with respect to their sensitivity to the early effects of noise exposure. Good discrimination between nonexposed and exposed ears was obtained using either the linear or the nonlinear mode. Despite its intrinsically higher SNR, the linear mode is not more sensitive than the nonlinear mode for this purpose because it is not possible to find a window for effectively cancelling the linear artifact while keeping a suitable sensitivity to the short-latency high-frequency aspect of the response. Moreover, with respect to another measurable parameter, the TEOAE latency, good discrimination is obtained only by using the nonlinear mode because, again, the linear artifact masks the high-frequency TEOAE response.     

TEOAE recording protocols revised: data from adult subjects

The objective of this study was the experimental re-evaluation of the current clinical transiently evoked otoacoustic emission (TEOAE) protocols, based on linear and non-linear protocol paradigms from a population of 42 adult subjects serving as a normative database. The linear and non-linear TEOAE responses were elicited by clicks with average intensities of 72 and 84 dB p.e. SPL respectively. An initial comparison between non-processed non-linear and linear recordings, at early recording segments from 3.2 to 5.2 ms, showed that the responses had highly similar contours and no statistically significant mean differences. The stimulus-induced artefact in the linear TEOAE responses was suppressed by post-processing the data with a window function (3.8-13.8 ms) and by a high-pass filter at 830 Hz. A repeated-measures model was used to evaluate the differences between post-processed linear and non-linear responses across clinical variables of interest (such as TEOAE response, noise, correlation, and signal-to-noise ratios (SNRs) at 1.0-5.0 kHz). The data indicated that the linear recordings demonstrate significantly lower levels of noise (and thus superior SNRs) and higher values of reproducibility. Normative adult scoring criteria were calculated from free distribution tolerance intervals for the TEOAE correlation and the SNRs at 2.0 and 3.0 kHz.     

新生儿与成人瞬态诱发耳声发射性别差异的比较

目的探讨瞬态诱发耳声发射(TEOAE)的性别差异在新生儿与成人之间的变化。方法以短声刺激分别对120名(女62,男58)通过听力筛查的新生儿及53名(男26,女27)纯音听阈正常的青年成人行TEOAE检测,对两组TEOAE强度及频带信噪比(SNR)的性别差异进行分析。结果①成人组TEOAE强度性别差异(2.41dB)明显高于新生儿(0.99dB)。②新生儿SNR除1kHz男婴高于女婴外,其余频带均为女婴高于男婴,且SNR的性别差异随频率增加而增大,在3、4kHz差异有统计学意义(P<0.05)。成人不同频带SNR均为女性高于男性,除3kHz外也呈现随频率增加而增大的特征,在2、4kHz差异有统计学意义(P<0.05)。结论 TEOAE总强度的性别差异随年龄增加而增大,且新生儿及成人频带SNR的性别差异均随频率增加而增大,成人低频区SNR的性别差异较新生儿更明显。     

Otoacoustic emissions in 28 young adults exposed to amplified music.

Popular concern about widespread damage to the hearing from exposure to amplified music continues, although there has been little firm evidence of permanent effects in casual listeners. Measurement of transient evoked otoacoustic emissions (TEOAEs) provides a sensitive technique for testing outer hair cell (OHC) function, and was used in this study of 28 young adults aged 18-25 years, whose only significant source of noise exposure was loud music, to look for evidence of poorer cochlear function in those of greater exposure; they provided 27 right ears and 27 left ears suitable for measurement of TEOAE strength. Estimates of subjects' total noise dose were obtained from self-reports of the duration and intensity of their exposure to music and other sources of noise. Ears with greater exposure to loud music showed significantly weaker TEOAEs than less exposed ears in response to a 4 kHz tone burst, or in response to a saturating (82 dBSPL) click if the response was treated with a high-frequency bandpass filter (2-4 kHz) (p<0.05). Differences between more exposed and less exposed groups of ears were most marked in the 2 kHz half-octave band for right ears, and in the 2.8 kHz half-octave band for left ears. A hypothesis is proposed that weakness in TEOAEs as a result of exposure to loud music is seen first in the 2 kHz region of the emission spectrum, and later at higher frequencies; and that for a given amount of exposure, TEOAE weakness (or OHC damage) is more advanced in left ears than in right.     

Modification of the Threshold Equalising Noise (TEN) test for cochlear dead regions for use with steeply sloping high-frequency hearing loss

Steeply sloping high-frequency hearing loss is often associated with cochlear dead regions. These can be identified by measuring pure-tone thresholds in quiet and in Threshold-Equalising Noise (TEN). However, many patients cannot be adequately tested because the low frequencies in the TEN lead to uncomfortable loudness. We investigated the effect of high-pass filtering on the TEN-test results and the loudness of the TEN. Twenty-four normally hearing subjects and 35 subjects with steeply sloping high-frequency hearing loss were tested, using the standard TEN (TENs), and TEN high-pass filtered at 0.5 kHz (TEN0.5) or 1 kHz (TEN1). For both groups, masked thresholds did not differ across noise types for frequencies above 1 kHz. Over 50% of the hearing-impaired ears tested met the criteria for a dead region at 4 kHz, using all three noise types. However, masked thresholds and the prevalence of positive TEN-test results at 1 kHz were both lower with the TEN 1. The TEN1 was judged the most comfortable noise by 68% of the hearing-impaired subjects. We conclude that high-pass filtering would allow testing at higher TEN levels for patients with steeply sloping hearing loss.     

Effects of high-pass filtering on the detection of the auditory brainstem response

The effects of high-pass filtering on the slow components of the click-evoked auditory brainstem response (ABR) have been assessed in eight normally hearing adults. Eight high-pass Butterworth-type filters (36 dB/octave) were investigated with cut-off frequencies at 10, 20, 30, 40, 50, 60, 80 and 100 Hz (-3 dB points). The low-pass filter was kept constant at 1 kHz. A 20 dB nHL stimulus was presented to the subjects at a rate of 26/s. Two averaged ABR waveforms, each consisting of 2048 individual sweeps, were recorded for each filter setting with a post-stimulus sweep time of 19.2 ms. In the visual interpretation of the recordings the correlation between each waveform, and the amplitude of the response relative to the noise, strongly affects the decision as to whether a response is present. A mathematical analysis of these parameters, using a scanning correlation window technique, showed that a 20 Hz filter is optimum for the best detection of the ABR close to hearing threshold.     

Development of auditory asymmetry in transient evoked otoacoustic emissions in pre-term infants

We previously reported that transient evoked otoacoustic emissions (TEOAEs) continue to develop after the onset of cochlear function in pre-term infants from 34 to 39 weeks of conceptional age (Morlet et al., 1996). The time-course of development differed between genders. Reported here are findings of further analysis of data from the study cohort, comprising 1020 ears of 510 pre-term neonates (conceptional age ranging from 34 to 39 weeks), demonstrating developmental differences between right and left ears. The left ear of female pre-term infants showed enhancement of TEOAE amplitude at low and medium frequencies with age, whereas differences were less dramatic in the right ear. In male infants, TEOAE amplitude decreased in several frequency bands at high frequencies, above 4 kHz, between 34 and 39 weeks conceptional age; most developmental differences were found to be more dramatic in the right than in the left ear. It is tempting to speculate that these developmental features underlie well-known inter-aural asymmetries that have been demonstrated in the adult human.     

NICU患儿听力筛查结果分析

目的分析新生儿重症监护病房（NICU）患儿听力筛查结果。方法对2008年1月～2009年1月间3130例NICU患儿用TEOAE初筛、复筛,对复筛未通过患儿行ABR诊断性检查。结果未通过TEOAE初、复筛的513例（709耳）患儿中,以早产儿和肺部疾患阳性率最高,其中102例（156耳）患儿经诊断性ABR检查,确诊为听力损失130耳（83．33％,130／156）,其中轻度听力损失38耳,中度55耳,中重度15耳,重度16耳,极重度6耳,肺部疾患、高胆红素血症和早产儿阳性率最高。结论NICU患儿听力损失发生率高,肺部疾病、高胆红素血症和早产儿是引起听力损失最主要的高危因素。