Tone burst stimulus for auditory brainstem responses: Prediction of hearing threshold at 1 kHz

Objective

To assess differences in hearing threshold estimation of four different ABR tone-bursts at 1 kHz.

Methods

Twenty-one (21) ears from 11 subjects were tested with pure-tone audiometry (PTA): 5 ears (24%) were normal hearing, 5 (24%) affected by mild hearing loss, 7 (33%) showed moderate hearing loss and 4 (19%) severe hearing loss. After PTA each subject underwent tone-burst ABR test at 1 kHz using a linear gated (L_ABR) or Blackman windowed (B_ABR) stimuli with (nn_ABR) and without ipsilateral notched noise. Stimulation rate and filters settings were unchanged.

Results

Overall correlation between PTA and all ABRs thresholds was high, ranging from 0.84 to 0.94. In normal hearing ears none of the differences was significant, except for those measured with B_nn_ABR, which showed a mean 16 dB overestimation of the pure-tone threshold (p < 0.05). In mild hearing loss group none of the differences between thresholds were significant. In moderate and severe hearing loss groups significant differences were measured with L_nn_ABR (p < 0.05) with a mean 7.5 dB underestimation of PTA.

Conclusions

Although very similar, some significant differences were found when considering specific group of patients with different degrees of hearing loss.     

Prevalence of dead regions in subjects with sensorineural hearing loss

OBJECTIVE: To estimate the prevalence of dead regions in adult subjects with sensorineural hearing impairment as a function of audiometric threshold and frequency and to assess the extent to which the presence/absence of a dead region can be predicted from the audiogram, gender, or age. DESIGN: Data were obtained from a random sample of adults attending an audiology clinic in Mysore, India. Audiometric air and bone conduction thresholds and tympanometry were used to identify 317 subjects (592 ears) with sensorineural hearing loss. Their ages ranged from 17 to 95 yr (mean = 57 yr). The threshold-equalizing noise hearing level (TEN (HL)) test, administered using the TEN(HL)-test CD and an audiometer, was used to determine the presence or absence of dead regions in these subjects for test frequencies ranging from 0.5 to 4 kHz. Nine subjects had to be excluded as the absolute thresholds were too high for the TEN(HL) test to be administered. Of the remaining 308 subjects (556 ears), 209 (68%) were male and 99 (32%) were female. The hearing losses ranged from mild to severe. RESULTS: Results are presented only for frequencies and ears for which the TEN level could be made high enough to produce at least 10 dB of masking. Classifying by subject, 177 (57.4%) were found to have a dead region in one or both ears for at least one frequency. Fifty-four women (54.5%) and 123 men (58.8%) had dead regions in one or both ears. Classifying by ear, 256 (46%) were diagnosed as having a dead region at one frequency or more: 233 ears (41.9%) had only a high-frequency dead region, 13 ears (2.3%) had only a low-frequency dead region, and 10 ears (1.8%) had a dead region at both low and high frequencies, with a surviving middle-frequency region. It was not possible to achieve both high sensitivity and high specificity when attempting to predict the presence/absence of a dead region from the audiogram. However, for each test frequency, 59% or more of ears had a dead region when the absolute threshold was above 70 dB HL. A very steep slope of the audiogram is suggestive of a high-frequency dead region but does not provide a reliable diagnostic method. Chi-square tests indicated that the prevalence of dead regions did not vary significantly with age or gender. CONCLUSIONS: The results indicate a relatively high prevalence of dead regions in adults with sensorineural hearing impairment, especially for frequencies at which the hearing loss exceeds 70 dB HL.     

单音节最大言语识别率与纯音听力不成比例下降的判定

目的 建立汉语普通话单音节最大言语识别率与纯音听力不成比例下降的判定标准.方法 对165名确诊为感音神经性聋的患者使用ER-3A插入式耳机分别进行双耳纯音测听和言语测听.以自行编制的言语测听软件播放音位平衡的普通话单音节测听表,每表25个单音节测试项的播放顺序可实现随机.同一耳别始终使用同一张表,以该耳所有纯音测听频率中的最小听阈减去5 dB作为起始测听强度,以5 dB为步距逐渐提高测试强度,获得患者该侧耳的言语识别率-强度(P-I)函数关系,读取最大言语识别率PBmax.根据气导纯音听力图计算三频率平均纯音听阈(pure tone average,PTA)PTA1(0.5、1、2 kHz)、PTA2(1、2、4 kHz)以及四频率平均纯音听阈PTA3(0.5、1、2、4 kHz);同时计算0.5、1、2 kHz与4 kHz纯音听阈的差值Slope0.5、Slope1、Slope2作为听力图高频走势的指征.利用SPSS10.0统计软件分析PBmax与以上因素的相关性.结果 PBmax与听力图高频走势Slope无相关性,但与纯音听阈呈负相关,尤与PTA3相关性最大(r=-0.595,P=0.000).基于由PBmax与PTA3所绘制的散点图的下缘,可建立起包含99%观测值的言语识别率下限,其函数表达式为PBmax=100-10×PTA3/11.结论 感音神经性聋患者依据纯音0.5、1、2、4 kHz的平均听阈可确定其言语识别率下限,PBmax得分若低于此界限,则可认定其言语识别率与纯音听力不成比例地下降.     

单音节最大言语识别率与纯音听力不成比例下降的判定

目的 建立汉语普通话单音节最大言语识别率与纯音听力不成比例下降的判定标准.方法 对165名确诊为感音神经性聋的患者使用ER-3A插入式耳机分别进行双耳纯音测听和言语测听.以自行编制的言语测听软件播放音位平衡的普通话单音节测听表,每表25个单音节测试项的播放顺序可实现随机.同一耳别始终使用同一张表,以该耳所有纯音测听频率中的最小听阈减去5 dB作为起始测听强度,以5 dB为步距逐渐提高测试强度,获得患者该侧耳的言语识别率-强度(P-I)函数关系,读取最大言语识别率PBmax.根据气导纯音听力图计算三频率平均纯音听阈(pure tone average,PTA)PTA1(0.5、1、2 kHz)、PTA2(1、2、4 kHz)以及四频率平均纯音听阈PTA3(0.5、1、2、4 kHz);同时计算0.5、1、2 kHz与4 kHz纯音听阈的差值Slope0.5、Slope1、Slope2作为听力图高频走势的指征.利用SPSS10.0统计软件分析PBmax与以上因素的相关性.结果 PBmax与听力图高频走势Slope无相关性,但与纯音听阈呈负相关,尤与PTA3相关性最大(r=-0.595,P=0.000).基于由PBmax与PTA3所绘制的散点图的下缘,可建立起包含99%观测值的言语识别率下限,其函数表达式为PBmax=100-10×PTA3/11.结论 感音神经性聋患者依据纯音0.5、1、2、4 kHz的平均听阈可确定其言语识别率下限,PBmax得分若低于此界限,则可认定其言语识别率与纯音听力不成比例地下降.     

单音节最大言语识别率与纯音听力不成比例下降的判定

目的 建立汉语普通话单音节最大言语识别率与纯音听力不成比例下降的判定标准.方法 对165名确诊为感音神经性聋的患者使用ER-3A插入式耳机分别进行双耳纯音测听和言语测听.以自行编制的言语测听软件播放音位平衡的普通话单音节测听表,每表25个单音节测试项的播放顺序可实现随机.同一耳别始终使用同一张表,以该耳所有纯音测听频率中的最小听阈减去5 dB作为起始测听强度,以5 dB为步距逐渐提高测试强度,获得患者该侧耳的言语识别率-强度(P-I)函数关系,读取最大言语识别率PBmax.根据气导纯音听力图计算三频率平均纯音听阈(pure tone average,PTA)PTA1(0.5、1、2 kHz)、PTA2(1、2、4 kHz)以及四频率平均纯音听阈PTA3(0.5、1、2、4 kHz);同时计算0.5、1、2 kHz与4 kHz纯音听阈的差值Slope0.5、Slope1、Slope2作为听力图高频走势的指征.利用SPSS10.0统计软件分析PBmax与以上因素的相关性.结果 PBmax与听力图高频走势Slope无相关性,但与纯音听阈呈负相关,尤与PTA3相关性最大(r=-0.595,P=0.000).基于由PBmax与PTA3所绘制的散点图的下缘,可建立起包含99%观测值的言语识别率下限,其函数表达式为PBmax=100-10×PTA3/11.结论 感音神经性聋患者依据纯音0.5、1、2、4 kHz的平均听阈可确定其言语识别率下限,PBmax得分若低于此界限,则可认定其言语识别率与纯音听力不成比例地下降.     

以听力突然下降为特征的分泌性中耳炎（附24例报告）

目的：提高对以听力突然下降为特征的分泌性中耳炎的确诊率。方法：回顾性分析24例（28耳）以听力突然下降为特征的分泌性中耳炎的临床资料,结果：11例患者被误诊或漏诊,各频率的平均气导阈值在60．2－66．5dBHL,平均骨导阈值在40．5－58．6dBHL,听力图示感音神经性聋9耳,混合性聋19耳,鼓室压图为B型,治疗后听力明显改善,结论,鼓室积液影响圆窗及卵圆窗间的相位差,导致听力突下降,它们的听力图无特征,并对产生误诊的原因进行了讨论。     

Relationship between pure tone audiometry and tone burst auditory brainstem response at low frequencies gated with Blackman window

To assess the reliability of Blackman windowed tone burst auditory brainstem response (ABR) as a predictor of hearing threshold at low frequencies. Fifty-six subjects were divided in to three groups (normal hearing, conductive hearing loss, sensorineural hearing loss) after pure tone audiometry (PTA) testing. Then they underwent tone burst ABR using Blackman windowed stimuli at 0.5 kHz and 1 kHz. Results were compared with PTA threshold. Mean threshold differences between PTA and ABR ranged between 11 dB at 0.5 kHz and 14 dB at 1 kHz. ABR threshold was worse than PTA in each but 2 cases. Mean discrepancy between the two thresholds was about 20 dB in normal hearing, reducing in presence of hearing loss, without any differences in conductive and sensorineural cases. Tone burst ABR is a good predictor of hearing threshold at low frequencies, in case of suspected hearing loss. Further studies are recommended to evaluate an ipsilateral masking such as notched noise to ensure greater frequency specificity.     

老年性聋患者普通话快速噪声下言语测试及评估

目的评估老年性聋患者噪声下言语识别能力,探讨年龄、听力损失程度、认知功能对其噪声下言语识别能力的影响。方法选取2018年10月~2020年4月就诊的70例60岁及以上老年性聋患者为研究对象,按年龄分为60~69岁(20例40耳)、70~79岁(28例56耳)、≥80岁(22例44耳)三组,各组分别进行纯音听阈测试、简易智能精神状态量表(mini-mental state examination,MMSE)评估及普通话快速噪声下言语测试(Mandarin quick speech-in-noise test,M-Quick SIN),分别获得双耳0.5、1、2、4 kHz纯音平均听阈(pure-tone audiometry,PTA)、MMSE量表总得分及双耳信噪比损失(signal-to-noise ratio loss,SNR loss);分析年龄、平均听阈、MMSE量表得分对信噪比损失的影响。结果①60~69岁组SNR loss(5.25±5.42)dB明显小于70~79岁组(11.54±6.05)dB和≥80岁组(11.86±6.06)dB(P<0.01);70~79岁组和≥80岁组间SNR loss差异无统计学意义(P>0.05)。②SNR loss随PTA提高而升高,各组间差异均有显著统计学意义(P<0.01)。③MMSE量表得分对SNR loss的主效应不显著(P>0.05)。结论年龄、听力损失程度为老年性聋患者噪声下言语识别的主要影响因素;在一定范围内随着年龄增加,听力损失加重,其噪声下言语识别能力降低。     

儿童chirp听性脑干反应与行为测听的相关性

目的 采用chirp信号作为声刺激进行听性脑干反应(ABR)测试,观察chirp ABR阈值与行为测听的相关性,探讨chirp ABR作为儿童临床客观听力评估的可行性.方法 选择2007年8月至9月佛山市听觉语言康复中心的听力障碍儿童和广州市儿童医院听力门诊的正常听力儿童共22例(共35耳)作为研究对象,分别进行行为测听和chirp ABR测试,并对chirp ABR反应阈和行为测听阈值进行Pearson相关性分析.结果 22例接受测试儿童中男14例,女8例,年龄3.3～6.5岁,平均年龄4.8岁.纳入研究的35耳中,正常听力6耳,听力损失轻度2耳、中度4耳、重度10耳、极重度13耳.行为测听0.5、1、2、4 kHz平均听阈与chirp ABR阈值,0.5 kHz听阈与L-chirp ABR阈值,1～4kHz平均听阈与U-chirp ABR阈值之间的相关系数分别为0.939,0.900及0.930,P值均<0.05.结论 chirp ABR作为一种客观测听技术,能够较好地反映儿童的听力水平,有希望应用到临床工作中.     

Hypersensitivity of hydropic ears, at frequencies with normal thresholds, to temporary threshold shifts

We have shown that experimentally-induced hydrops in the guinea pig systematically provokes an early low frequency (6.4 kHz and below) fluctuant hearing loss. The present study was aimed at investigating one aspect of the functioning of that part of the audiogram with normal CAP thresholds (mid and high frequencies) in early hydrops. Temporary threshold shifts (TTS) as a function of pure tone stimulation level (8 kHz, 1 min 75-95 dB SPL), were investigated. The TTS was measured as a function of pure-tone exposure level. The different points on the input/output curve were determined on sequential days in order to allow full recuperation from the previous stimulation. The group of hydropic ears (N = 5) proved to be more sensitive by about 6 dB than the group of control ears (N = 10). The data indicate that whilst short-term endolymphatic hydrops can be characterised by a selective low frequency loss other auditory deficits exist throughout the cochlea and become manifest at supraliminal stimulus levels.     

Audiometric predictions using stimulus-frequency otoacoustic emissions and middle ear measurements

OBJECTIVE: The goals of the study are to determine how well stimulus-frequency otoacoustic emissions (SFOAEs) identify hearing loss, classify hearing loss as mild or moderate-severe, and correlate with pure-tone thresholds in a population of adults with normal middle ear function. Other goals are to determine if middle ear function as assessed by wideband acoustic transfer function (ATF) measurements in the ear canal account for the variability in normal thresholds, and if the inclusion of ATFs improves the ability of SFOAEs to identify hearing loss and predict pure-tone thresholds. DESIGN: The total suppressed SFOAE signal and its corresponding noise were recorded in 85 ears (22 normal ears and 63 ears with sensorineural hearing loss) at octave frequencies from 0.5 to 8 kHz, using a nonlinear residual method. SFOAEs were recorded a second time in three impaired ears to assess repeatability. Ambient-pressure ATFs were obtained in all but one of these 85 ears and were also obtained from an additional 31 normal-hearing subjects in whom SFOAE data were not obtained. Pure-tone air and bone conduction thresholds and 226-Hz tympanograms were obtained on all subjects. Normal tympanometry and the absence of air-bone gaps were used to screen subjects for normal middle ear function. Clinical decision theory was used to assess the performance of SFOAE and ATF predictors in classifying ears as normal or impaired, and linear regression analysis was used to test the ability of SFOAE and ATF variables to predict the air conduction audiogram. RESULTS: The ability of SFOAEs to classify ears as normal or hearing impaired was significant at all test frequencies. The ability of SFOAEs to classify impaired ears as either mild or moderate-severe was significant at test frequencies from 0.5 to 4 kHz. SFOAEs were present in cases of severe hearing loss. SFOAEs were also significantly correlated with air conduction thresholds from 0.5 to 8 kHz. The best performance occurred with the use of the SFOAE signal-to-noise ratio as the predictor, and the overall best performance was at 2 kHz. The SFOAE signal-to-noise measures were repeatable to within 3.5 dB in impaired ears. The ATF measures explained up to 25% of the variance in the normal audiogram; however, ATF measures did not improve SFOAEs predictors of hearing loss except at 4 kHz. CONCLUSIONS: In common with other OAE types, SFOAEs are capable of identifying the presence of hearing loss. In particular, SFOAEs performed better than distortion-product and click-evoked OAEs in predicting auditory status at 0.5 kHz; SFOAE performance was similar to that of other OAE types at higher frequencies except for a slight performance reduction at 4 kHz. Because SFOAEs were detected in ears with mild to severe cases of hearing loss, they may also provide an estimate of the classification of hearing loss. Although SFOAEs were significantly correlated with hearing threshold, they do not appear to have clinical utility in predicting a specific behavioral threshold. Information on middle ear status as assessed by ATF measures offered minimal improvement in SFOAE predictions of auditory status in a population of normal and impaired ears with normal middle ear function. However, ATF variables did explain a significant fraction of the variability in the audiograms of normal ears, suggesting that audiometric thresholds in normal ears are partially constrained by middle ear function as assessed by ATF tests.     

Evidence of hearing loss in a 'normally-hearing' college-student population

We report pure-tone hearing threshold findings in 56 college students. All subjects reported normal hearing during telephone interviews, yet not all subjects had normal sensitivity as defined by well-accepted criteria. At one or more test frequencies (0.25-8 kHz), 7% of ears had thresholds ≥25 dB HL and 12% had thresholds ≥20 dB HL. The proportion of ears with abnormal findings decreased when three-frequency pure-tone-averages were used. Low-frequency PTA hearing loss was detected in 2.7% of ears and high-frequency PTA hearing loss was detected in 7.1% of ears; however, there was little evidence for 'notched' audiograms. There was a statistically reliable relationship in which personal music player use was correlated with decreased hearing status in male subjects. Routine screening and education regarding hearing loss risk factors are critical as college students do not always self-identify early changes in hearing. Large-scale systematic investigations of college students' hearing status appear to be warranted; the current sample size was not adequate to precisely measure potential contributions of different sound sources to the elevated thresholds measured in some subjects.     

多频听性稳态反应评估听力正常青年人纯音听阈的探讨

目的　探讨多频听性稳态反应(multipleauditorysteadystateresponse ,MASSR)评估听力正常青年人纯音听阈的可靠性。方法　对2 8名( 5 6耳)听力正常青年人进行MASSR及纯音听阈检查,记录0 .5、1、2、4kHz反应阈及行为听阈,比较二者间的相关性。结果　MASSR反应阈左右耳间无显著性差异;各频率间MASSR反应阈比较,0 .5kHz较其他各频率有显著性差异(P <0 .0 0 1) ,1、2、4kHz三个频率间均无显著性差异(P >0 .0 5 )。MASSR反应阈与纯音听阈在0 .5、1、2、4kHz相关系数分别为0 .71、0 .83、0 .86、0 .87。结论　MASSR反应阈与纯音听阈间有较好的相关性,MASSR可用于评估纯音听阈     

Bilateral hearing loss due to a meningioma located in the left posterior fossa: a case report

We report the case of a 39-year-old woman with a left side meningioma, suffering from bilateral sensorineural hearing loss, who recovered audiometric hearing in both ears after surgery. A preoperative pure tone audiogram (PTA) revealed a bilateral sensorineural hearing loss. Several examinations for sensorineural hearing loss indicated cochlear and retrocochlear hearing loss in the left ear and cochlear hearing loss in the right ear. After the operation, bilateral hearing loss due to a left posterior fossa meningioma gradually improved. One year after surgery, with the exception of hearing at frequencies of 4 and 8 kHz in the left ear, the postoperative audiogram had improved to an almost normal level. We speculate that hearing loss in the left ear may have been induced by the indirect compression of the cochlear nerve caused by the tumor's edema, whereas that in the right ear may have resulted from changes in CSF pressure caused by the mass effects of the tumor.     

Summating potentials in Menière's disease.

The summating potentials in response to tonebursts of 2, 4, and 8 kHz were studied in a group of 112 patients diagnosed as having Menière's disease, and the results were compared with recordings from 27 normal human ears. Subdivision of the Menière ears into a low-threshold (threshold less than 50 dB HL) and a high-threshold group (greater than 50 dB HL) proved to be functional in relation to the behaviour of the SP. The data of the low-threshold Menière group did not differ significantly from the normal data, whereas the high-threshold Menière group showed significantly smaller summating potentials. Up to hearing thresholds of 50 dB, the detection threshold for the SP was independent of the hearing threshold; at higher hearing losses, the increase in SP threshold equalled the increase in hearing loss. Analysis showed that the correlation found between the changes in SP and hearing threshold in individual patients did not differ significantly from zero for threshold values below 50 dB. The overall conclusion is that in Menière ears hearing losses up to about 50 dB are not related to changes in the hair cells, since the SP does not change, whereas the increase in the amount of hearing loss above 50 dB HL is paralleled by a loss in sensitivity of the summating potential and is therefore related to a functional loss of hair cells.     

Functional hearing loss in children

This report reviewed 39 school-age children diagnosed as having a functional hearing loss utilizing auditory brainstem response (ABR) audiometry during the past 5 years at the Department of Otolaryngology, Kyushu University Hospital in Japan. Twenty-seven cases were females and 12 were males. Seven cases had a hearing loss unilaterally and 32 bilaterally. Although pure-tone audiometry revealed a variety of audiogram shapes, two-thirds of the cases had a flat or saucer-shaped audiogram with a mild to moderately severe hearing loss. ABR audiometry for the frequencies of 1, 2 and 4 kHz indicated a normal hearing threshold in 65 ears of 35 patients, and mild threshold elevations of at least one frequency in the remaining 6 ears of 4 patients. Three illustrative cases were demonstrated, and a discussion was held regarding the features in audiometric tests, and environmental factors surrounding the children with this condition. We emphasized that the physiological hearing measurement such as ABR audiometry should be performed when any discrepancy was noted between the patient's history and results of pure-tone audiometry, because of not infrequent occurrence of functional hearing loss.     

Changes in otoacoustic emissions and high-frequency hearing thresholds in children and adolescents

With the aim of characterizing the loss of high frequency hearing sensitivity in children, hearing thresholds and otoacoustic emissions were measured in a group of 126 normal hearing children and adolescents aged from 6 to 25 years. The subjects were divided into four 5-year age groups. Hearing thresholds over a range of 125 Hz-12.5 kHz were similar in all age groups, the average hearing threshold at 16 kHz was significantly elevated in the oldest age group. The response values of transiently evoked otoacoustic emissions (TEOAEs) significantly declined with age; the decline was negatively correlated with the hearing loss at 16 kHz. Significantly larger TEOAE responses and average distortion-product otoacoustic emission (DPOAE) values at 6.3 kHz were present in the youngest group in comparison with the other three older groups. Spontaneous otoacoustic emissions (SOAEs) were present in 70.8% of the children (in either one or both ears) with the greatest prevalence in the 11-20-year-old subjects. In the 21-25-year-old group, the hearing loss at 16 kHz was significantly smaller in ears with SOAEs than in ears without SOAEs. The results demonstrate that the increase in the high frequency hearing threshold at 16 kHz, which starts at ages over 20 years, is correlated with a decrease in the TEOAE responses at middle frequencies.     

听神经病106例听力学分析

目的 分析106例听神经病患者的临床特点和听力学测试结果.探讨听神经病纯音听力图和听性脑干反应(ABR)的特点.方法 回顾性分析2001年12月至2007年5月就诊的106例(212耳)听神经病患者的症状及纯音听阈、声导抗图及镫骨肌反射、ABR、畸变产物耳声发射(DPOAE)和颅脑影像学检查的结果.结果 患者中男54例,女52例;年龄11～37岁,以青少年居多(75例,70.8%).伴有其他外周神经病者8例,伴视神经病者4例,未查出明确病因者94例.患者均为双耳发病.在212耳中,有173耳(81.6%)听力下降最多的频率为0.25 kHz和0.5 kHz.轻至中度听力损失共209耳(98.6%),均为感音神经性听力损失.按WHO(1997)听阈的均值计算法统计,本组有49耳(23.1%)的听阈≤25 dB,按WHO推荐的听力减退分级标准,使这些有听力障碍的病耳列入了正常范围.212耳听性脑干反应的测试中,各波形皆未引出者124耳(58.5%),余88耳有1或2个波未引出,而可引出的波的波幅很小,但有重复性.在1或2个可引出小波病例中,有23例其另1侧耳各波皆缺失.另有2例伴其他周围神经病和1例伴视神经病的患者,其双耳均有1或2个小波可引出.畸变产物耳声发射除1例左侧3～6 kHz,右侧5～6 kHz未引出外,余均可引出.结论 听神经病在青少年中并不罕见.因听神经病大多以低频听力下降为主,对听神经病患者平均听阈的计算方法值得讨论.     

Summating potentials in Menière's disease

Summary The summating potentials in response to tonebursts of 2, 4, and 8 kHz were studied in a group of 112 patients diagnosed as having Menière's disease, and the results were compared with recordings from 27 normal human ears. Subdivision of the Menière ears into a low-threshold (threshold <50 dB HL) and a high-threshold group (>50 dB HL) proved to be functional in relation to the behaviour of the SP. The data of the low-threshold Menière group did not differ significantly from the normal data, whereas the high-threshold Menière group showed significantly smaller summating potentials. Up to hearing thresholds of 50 dB, the detection threshold for the SP was independent of the hearing threshold; at higher hearing losses, the increase in SP threshold equalled the increase in hearing loss. Analysis showed that the correlation found between the changes in SP and hearing threshold in individual patients did not differ significantly from zero for threshold values below 50 dB. The overall conclusion is that in Menière ears hearing losses up to about 50 dB are not related to changes in the hair cells, since the SP does not change, whereas the increase in the amount of hearing loss above 50 dB HL is paralleled by a loss in sensitivity of the summating potential and is therefore related to a functional loss of hair cells.