Click- and tone-burst-evoked otoacoustic emissions in normally hearing ears and in ears with high-frequency sensorineural hearing loss

Summary Otoacoustic emissions (OAEs) evoked by clicks and tone bursts (TBs) were measured using a minor modification of the 1987 Bray and Kemp system in normal and hearing-impaired ears with high-frequency sensorineural hearing loss. Sixty ears of 60 subjects were tested. The average behavioral hearing threshold of 20 normally hearing ears was measured for the different nonlinear stimulus groups and defined as 0 dBnHL. Emissions were recorded in another 20 normally hearing ears and in 20 ears with steep high-frequency sensorineural hearing loss above 2 kHz. An unfiltered click of 80 s duration and TBs at frequencies of 0.5, 1, 2, 3, 4, 5, and 6 kHz served as stimuli. The ears with high-frequency hearing loss were clearly distinguished from the normal ears in that emission energy decreased with higher frequency stimuli above 2 kHz. The mean slopes of the response-growth functions were significantly higher at lower audiometric thresholds. The normal ears showed a slope of 0.21–0.35dB/dBnHL above 2kHz while the slope of the pathological ears was 0.04–0.13 dB/dBnHL. These differences in TBOAEs could possibly be used clinically to carry out hearing tests that are more frequency-specific than those measuring solely click-evoked OAEs. Pathological ears had emissions in the lower frequency range, where they had a normal audiometric threshold. However, these emissions had significantly far lower amplitudes at frequencies around 0.5 and 1 kHz when compared to normal ears. This reduced emission energy may indicate a cochlear impairment of the pathological ears in frequency ranges where they still had normal audiometric thresholds.Portions of this report were presented at the ADANO (Arbeitsgemeinschaft Deutscher Audiologen und Neurotologen) Meeting in Flims, Switzerland, March 29–31, 1990 Offprint requests to: R. Hauser     

Evoked otoacoustic emissions and sensorineural hearing loss

Following Kemp's original studies, several others have confirmed the existence of otoacoustic emissions. Their clinical relevance remains, however, to be clarified. The various published studies have concerned small series. This study sought to specify otoacoustic emission characteristics in relation to sensorineural hearing loss (148 ears of 76 subjects). The results show that the presence of otoacoustic emissions drops as a function of hearing loss and that there is a highly statistically significant correlation between otoacoustic emission threshold and hearing loss at the 1000-Hz frequency. Otoacoustic emissions are never found when hearing loss at 1000 Hz exceeds 40 dB hearing level and when the mean audiometric hearing loss (at 500, 1000, 2000, and 4000 Hz) exceeds 45 dB hearing level. The main practical conclusion is that otoacoustic emission presence indicates middle frequency functional integrity of the outer hair cells of Corti's organ. Absence of otoacoustic emissions is harder to interpret.     

Otoacoustic emissions value in patients with idiopathic sudden sensorineural hearing loss

ObjectivesThis study aimed to determine the prognostic value of otoacoustic emissions (OAEs) in idiopathic sudden sensorineural hearing loss patients.MethodsThe study included 30 subjects with unilateral idiopathic sudden sensorineural hearing loss (ISSNHL). Each patient was evaluated four times: at baseline and after one week, one month, and three months of treatment. During each visit, each patient was subjected to full audiological history, otoscopic examination, basic audiological evaluations, and transiently evoked and distortion product otoacoustic emission (TEOAEs & DEOAEs).ResultsThe hearing thresholds (frequency range 250–8000 Hz) and word recognition scores of patients with detectable TEOAEs and DPOAEs improved significantly, whereas no significant improvements were observed in those with no response.ConclusionHearing improvement is better in patients with detectable TEOAEs and DPOAEs. As a result, TEOAEs and DPOAEs are recommended as routine tests in all SSNHL patients to predict outcomes and monitor treatment as TEOAEs and DPOAEs reflect the cochlear OHCs activity.     

Characteristics of transient evoked otoacoustic emissions in normal-hearing and hearing-impaired children

OBJECTIVE: Transient evoked otoacoustic emissions (TEOAEs) were measured in children with normal hearing and in children with hearing loss to investigate the characteristics of TEOAEs as they relate to overall amplitude and amplitude spectra of evoking stimuli, and to audiometric status. DESIGN: Three parameters of response measure (signal to noise ratio, amplitude and reproducibility) were assessed to determine accuracy of identification of varying degrees of hearing loss for broadband clicks, frequency-specific click bands and tone bursts. Forty-four children (66 ears) between 4 and 13 yr of age were evaluated for participation in the study. Fifty-nine ears with intact tympanic membranes were included in the final analyses: 14 ears with normal hearing and 45 ears with hearing loss. RESULTS: Children with normal hearing had robust responses that displayed nonlinear growth functions for broadband clicks and for tone bursts. Children with hearing loss had responses that decreased rapidly with decreasing stimulus level, if emissions were present at all. Data were analyzed using clinical decision analysis and receiver operator characteristic curves. Broadband clicks presented at 80 and 86 dB peSPL identified a hearing loss > or = 30 dB HL with a high degree of accuracy. Click responses filtered into octave bands centered at 500 and 1000 Hz did not improve classification of hearing loss, in fact, the 500 Hz band was particularly inaccurate. Results for click responses filtered into half-octave bands centered at 2000 and 4000 Hz were comparable with those for the broadband click, although the 2000 Hz band was superior for identification of hearing loss > or = 20 dB HL for an 80 dB peSPL click, and > or = 30 dB HL for an 86 dB peSPL click. Results for tone bursts centered at 500, 1000, 2000 and 4000 Hz, presented at 80 dB peSPL, were similar to results of the filtered click bands. Accuracy for identifying hearing loss increased with increasing center frequency. The 2000 and 4000 Hz tone bursts provided the best separation between normal-hearing and hearing-impaired ears, with 4000 Hz being slightly better. CONCLUSIONS: Data from this study suggest that TEOAEs in children can separate ears with normal hearing from those with hearing loss using a variety of stimulus and response conditions. Moreover, by using multiple stimulus levels it may be possible to distinguish between mild and moderate hearing losses.     

低频感音神经性听力损失的病因分析

目的分析低频感音神经性听力损失的病因,以避免漏诊和误诊。方法对56例低频感音神经性听力损失患者详细了解其病史,进行仔细的耳科常规检查及纯音听阈（PTT）、声导抗、听性脑干反应（ABR）、畸变产物耳声发射（DPOAE）、耳蜗电图（ECochG）及CT和/或MRI检查,综合分析各项结果。结果在56例患者中病因不明的急性低频感音神经性听力损失38例,梅尼埃病9例,听神经病6例,听神经瘤1例,多发性硬化1例,小脑半球旁蛛网膜囊肿1例。结论低频听阈升高的上坡型感音神经性听力损失可见于多种疾病。对低频感音神经性听力损失应采用多项组合的听力学检测方法进行检查和综合分析,必要时辅以CT和/或MRI检查可以及时、有效地作出可靠的诊断和鉴别诊断。     

Audiological findings in otospondylomegaepiphyseal dysplasia (OSMED) associated with a novel mutation in COL11A2

The aim of the study was to assess the audiological findings of a 4-year-old child with a homozygous COL11A2 mutation and to point out the role of continuous follow-ups in children with craniofacial syndromes after the newborn hearing screening. A 4-year-old boy with otospondylomegaepiphyseal dysplasia (OSMED) was followed up after birth for hearing loss. Transient Otoacoustic Emissions (TEOAEs), Distortion Product Otoacoustic Emissions (DPOAEs), Automated and Clinical Auditory Brainstem Response (AABR and ABR) measurements, Visual Reinforcement Audiometry, immitansmetric measurements and hearing threshold measurements were performed for audiological evaluation. The patient developed sensorineural hearing loss at 11 months of age while his hearing was normal at birth. Because of auditory-verbal training with hearing aids started at 20 months of age, he now has normal verbal communication with his peers. This study clearly demonstrates that hearing loss develops in infancy in patients with OSMED and underscores the importance of continued hearing screening beyond newborn period for early intervention of hearing impairment and communication problems.     

Otoacoustic emissions: assessment of hearing after tympanostomy tube insertion

This study evaluates the use of transient evoked otoacoustic emissions as an alternative to pure tone audiometry for the assesment of hearing after tympanostomy tube insertion. Otoacoustic emissions and pure tone audiometry were carried out in 32 patients in whom tympanostomy tubes had been inserted. Otoacoustic emissions were detected in 78% of patients, whereas pure tone audiometry testing was only possible in 59%. Of 13 children who were 3 years of age or under, otoacoustic emissions could be measured in 62%, compared to pure tone audiometry which was only possible in 8%. Otoacoustic emission testing took on average 3 min, which was less than half the time for pure tone audiometry testing which took 7 min.     

Auditory brainstem responses to CE-Chirp® stimuli for normal ears and those with sensorineural hearing loss

Objective: Evaluation of the characteristic differences between click-and CE-Chirp-evoked auditory brainstem responses (ABRs) in normal hearing and sensorineural hearing loss. Design: A prospective study. Ears with normal hearing and with sensorineural hearing loss were evaluated. Pure-tone audiometry and click-and CE-Chirp evoked ABRs exams were conducted for all ears. Visual detection levels, wave-V amplitudes, and latencies of the ABRs were assessed. Study sample: Twenty-two ears with normal hearing and 22 ears with sloping type sensorineural hearing loss were examined. Results: In normal-hearing ears, mean amplitudes were larger for CE-chirps than for clicks at all intensities until 80 dB nHL, at which the amplitudes dropped off, presumably due to upward spread of excitation. In ears with sensorineural hearing loss, however the drop-off was less significant at 80 dB nHL. Comparisons with pure-tone audiometry findings revealed ABRs to CE-Chirps to correlate at 0.5, 1, 2, and 3 kHz, and to clicks at 1, 2, 3, and 4 kHz. Conclusions: The CE-Chirp has advantages over clicks for examining normal ears. However, under high-level stimulation, these advantages are no longer present. In ears with sensorineural hearing loss, the upward spread of excitation is less prominent. The CE-Chirps results correlate significantly to low frequency audiometric findings at 0.5 kHz, while clicks do not.     

Tympanometry with 226 and 1000 Hertz tone probes in infants

This study aimed at describing and analyzing tympanometric results obtained with 226Hz and 1000Hz probe tones; checking for correlations between tympanometry, otoacoustic emissions and otoscopic examination; describing abnormal results found in the evaluation procedures.MethodsDouble-blind and prospective study. Our sample included 70 babies, between 7 days and one month and 13 days of age, without risk indicators for hearing loss, evaluated in the State Neonatal Hearing Screening Program. Transient evoked otoacoustic emissions, otoscopic examination and tympanometry with 226Hz and 1000Hz probe tones were used as assessment tools. The study was approved by the Ethics Committee from the institution.ResultsStatistically significant differences were observed (p<0.05) in the tympanometric measures correlation and also between transient evoked otoacoustic emissions and compliance obtained with both probe tones. Most test results were within the normal range (94.28%). Three children (4.28%) were referred to diagnostic follow-up and one (1.42%) had middle ear dysfunction confirmed by otoscopy and 1000Hz tympanometry.Conclusions1000Hz tympanometry is the most reliable probe tone used to evaluate children under three months of age. More studies focusing on middle ear acoustics and mechanics are necessary to provide reliable and precise interpretation in the evaluation of middle ear functions in babies.     

Multi-variant Analysis of Otoacoustic Emissions and Estimation of Hearing Thresholds: Transient Evoked Otoacoustic Emissions

Evaluation of cochlear hearing loss by means of transiently evoked otoacoustic emissions is already established in clinical practice. However, accurate prediction of pure-tone thresholds is still questioned and is still regarded as troublesome. Both click- and tone-burst-evoked otoacoustic emissions at several intensity levels were measured and analysed in 157 ears from normally hearing and 432 ears from patients with different degrees of pure sensory hearing loss using the IL088/92 equipment. Results of otoacoustic emissions (OAE), elicited by clicks and tone-bursts at centre frequencies from 1 to 5 kHz, were analysed using two different statistical methods. Both multivariate discriminant analysis and forward multiple regression analysis were used to determine which OAE variables were most discriminating and best at predicting hearing thresholds. We found that a limited set of variables obtained from both tone-burst and click measurements can accurately predict and categorize hearing loss levels up to a limit of 60 dB HL. We found correct classification scores of pure-tone thresholds between 500 and 4000 Hz up to 100 per cent when using combined click and tone-burst otoacoustic measurements. Prediction of pure-tone thresholds was correct with a maximum estimation error of 10 dB for audiometric octave frequencies between 500 and 4000 Hz.

Measurements of multiple tone-bursts OAEs have a significant clinical advantage over the use of clicks alone for clinical applications, and a good classification and prediction of pure-tone thresholds with otoacoustic emissions is possible.     

On a possible prognostic value of otoacoustic emissions: a study on patients with sudden hearing loss

Otoacoustic emissions (OAE) and pure tone audiogram (PTA) were examined in 26 ears of 25 patients suffering from sudden hearing loss from the 1st day to up to 505 days following the drop of hearing to test the hypothesis whether the OAEs are capable of delivering predictive information about the recovery process. The patients were selected from 50 candidates according to the following criteria: one or both ears exhibited a systematic and significant recovery of pure tone threshold in at least one frequency, OAEs were detectable and PTA available, a conductive hearing loss was excluded, and the auditory brainstem responses (ABR) yielded no signs of retrocochlear disorders. Transitory evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) were measured under constant stimulus and recording conditions in three to nine sessions. The relation between OAE level and actual pure tone threshold was subject to a regression analysis. The correlation between both parameters is small but significant. Even smaller correlations are observed if the OAE level is related to former hearing loss, whereas the correlation improves if the OAE level is compared to the pure tone threshold measured in a later session. The slopes of individual trajectories that connect the successive results of one ear in a plane defined by hearing loss and OAE level show a remarkable accumulation around zero, i.e., in many cases the OAEs remain unchanged even if the hearing loss decreases. The comparison of the OAE levels measured at an early stage with later audiograms shows that there are only a small number of cases with small initial emissions and good final threshold or large initial emissions and bad final threshold. This means that small initial OAEs end up with a remaining final hearing deficit, whereas a high OAE level immediately after drop of threshold correlates with good outcome. The reliability of an individual prediction based on the OAE level combined with the threshold after sudden hearing loss and the consequences for the physiologic mechanisms underlying the sudden hearing loss remain to be proved in further investigations.     

Auditory neuropathy in childhood

Objectives: Auditory neuropathy is a recently described disorder in which patients demonstrate hearing loss for pure tones, impaired word discrimination out of proportion to pure tone loss, absent or abnormal auditory brainstem responses, and normal outer hair cell function as measured by otoacoustic emissions and cochlear microphonics. We have identified eight pediatric patients having hearing deficits that are most likely due to a neuropathy of the eighth nerve. In this study, the results of audiologic testing performed with these eight children are described. Study Design: Retrospective review of audiologic findings in eight children with auditory neuropathy. Methods. Each subject was tested with pure tone and speech audiologic testing, auditory brainstem response, and click-evoked otoacoustic emissions. Results of these tests were tabulated and summarized. Results: Pure tone audiologic testing revealed five children with upsloping sensorineural hearing loss, two with high frequency loss, and one with a mild, flat configuration. Six children demonstrated poor word discrimination scores, and the other two had fair to good word discrimination. All eight subjects had normal distortion product and transient otoacoustic emissions. All eight children demonstrated absent or marked abnormalities of brainstem auditory evoked potentials. These findings suggest that while cochlear outer hair cell function is normal, the lesion is located at the eighth nerve. Conclusions: Recent advances in otoacoustic emissions testing permit differentiation of neural deafness from sensory deafness. This paper describes the clinical presentation and audiologic findings in pediatric auditory neuropathy, as well as the recommended management of these patients. Otolaryngologists should be aware of this disorder and implications for its management, which differs from treatment of sensorineural hearing loss. Key Words: Auditory neuropathy, childhood, hearing loss, auditory brainstem response, evoked otoacoustic emissions.     

High frequency hearing thresholds and product distortion otoacoustic emissions in cystic fibrosis patients

IntroductionThe treatment of patients with cystic fibrosis involves the use of ototoxic drugs, mainly aminoglycoside antibiotics. Due to the use of these drugs, fibrocystic patients are at risk of developing hearing loss.ObjectiveTo evaluate the hearing of patients with cystic fibrosis by High Frequency Audiometry and Distortion Product Otoacoustic Emissions.MethodsCross-sectional study. The study group consisted of 39 patients (7–20 years of age) with cystic fibrosis and a control group of 36 individuals in the same age group without otologic complaints, with normal audiometric thresholds and type A tympanometric curves. High Frequency Audiometry and Distortion Product Otoacoustic Emissions tests were conducted.ResultsThe study group had significantly higher thresholds at 250, 1000, 8000, 9000, 10,000, 12,500, and 16,000 Hz (p = 0.004) as well as higher prevalence of otoacoustic emission alterations at 1000 and 6000 Hz (p = 0.001), with significantly lower amplitudes at 1000, 1400, and 6000 Hz. There was a significant association between alterations in hearing thresholds in High Frequency Audiometry with the number of courses of aminoglycosides administered (p = 0.005). Eighty-three percent of patients who completed more than ten courses of aminoglycosides had hearing loss in High Frequency Audiometry.ConclusionA significant number of patients with cystic fibrosis who received repeated courses of aminoglycosides showed alterations in High Frequency Audiometry and Distortion Product Otoacoustic Emissions. The implementation of ten or more aminoglycoside cycles was associated with alterations in High Frequency Audiometry.     

Threshold of the Early Components of the Averaged Electroencephalic Response Determined with Tone Pips and Clicks During Drug-Induced Sleep

The early components of the averaged electroencephalic response (AER) were elicited from eight adults by narrow-spectrum tone pips centered at 250, 1 000, and 4 000 Hz, and by wide-band clicks. Brief naps were induced with secobarbital. Stimuli at 0, 10, 20, and 30 dB above behavioral threshold were presented in random order for each frequency. Control conditions in which no acoustic stimuli were presented were also employed. Responses were stored on magnetic tape and later scored independently on a yes-no basis by two judges who employed predetermined response criteria. Threshold for hearing (50-percent response) as measured with the early components was 20 dB sensation level (SL) for 250 Hz tone pips, and at 10 dB SL for 1 000 and 4 000 Hz tone pips and clicks. Thus, threshold estimated with the early components of the AER from sleeping adults closely approximated their behavioral threshold     

Otoacoustic emissions in ears with hearing loss

Fifty ears of 37 patients demonstrating several common types of hearing impairment were examined for the presence of spontaneous and evoked otoacoustic emissions to investigate the relationship of acoustic emissions to hearing pathology. Of the 50 ears, 44 exhibited various degrees of sensorineural hearing loss. Evoked otoacoustic emissions to clicks were detected in 34 of 35 sensorineural hearing loss ears with a subjective click threshold less than 55 dB SPL (25 dB nHL). None of nine ears with sensorineural hearing impairment and a subjective click threshold greater than 55 dB SPL demonstrated click-evoked emissions. Spectral analyses revealed that the constituent frequency components of evoked emissions were always within the frequency range where audiometric thresholds were less than 35 dB HL, and in the majority (94%) of cases, thresholds were less than 25 dB HL. In ears with relatively well-preserved hearing within the frequency range of click or 1.5-kHz toneburst stimuli, the basic features of evoked emissions were similar to those described for normal ears. Similarly, for ears demonstrating spontaneous otoacoustic emissions, estimated audiometric thresholds at the emitted frequencies were always less than 20 dB HL. The influence of the type of otologic pathology on acoustic emissions was studied in a subset of ears exhibiting typical high-frequency hearing losses. Ears with a noise-induced impairment showed a significant reduction in the incidence of both spontaneous emissions and spectral peaks in evoked emissions that was not evident in ears with similar patterns of hearing loss caused by other factors.     

Comparison of pure tone and transient otoacoustic emissions screening in a grade school population

HYPOTHESIS: Otoacoustic emissions provide an alternative to traditional pure tone hearing screening in a diverse grade school population. BACKGROUND: Mandated pure tone hearing screening programs for grade school children have several significant limitations. Otoacoustic emissions have been shown to be a reliable screening test in newborns, but there are no data on screening a diverse grade school population. METHODS: Five hundred eighty-three grade school children in four separate school populations were screened for hearing loss using the standard pure tone four-frequency protocol and transient evoked otoacoustic emissions. Students failing either test received a comprehensive audiogram by an audiologist that served as the "gold standard." Sensitivity and specificity of both tests were compared. RESULTS: The sensitivity and specificity of pure tone screening was 87% and 80%, respectively, compared with 65% and 91% for transient evoked otoacoustic emissions. CONCLUSION: Pure tone screening was a statistically significant better screening test for detecting hearing loss in this population of grade school children.     

感音神经性聋成人不同刺激声ASSR反应阈与纯音听阈的相关性分析

目的探讨调制声听性稳态反应(ASSR)、 CE-Chirp ASSR用于评估感音神经性聋成人客观听力的价值。方法对78例(131耳)感音神经性聋成人同时进行纯音听阈和调制声ASSR、 CE-Chirp ASSR测试,比较0.5~4 kHz各频率纯音听阈与调制声ASSR、CE-Chirp ASSR反应阈的相关性及差值。结果 0.5、1、2、4 kHz CE-Chirp ASSR反应阈与纯音听阈的相关系数(分别为0.77、0.73、0.80、0.88)均高于调制声ASSR反应阈与纯音听阈的相关系数(分别为0.64、0.61、0.78、0.84),调制声ASSR、CE-Chirp ASSR反应阈与纯音听阈均具有显著相关性(圴为P<0.01);0.5~4 kHz CE-Chirp ASSR反应阈和纯音听阈的差值(分别为8.09±4.74、10.76±5.86、7.44±7.95、6.11±9.14 dB)均明显小于调制声ASSR反应阈和纯音听阈间的差值(分别为14.31±6.38、13.85±6.25、17.17±6.29、13.58±4.35 dB),差异均有统计学意义(均为P<0.05)。结论 CE-Chirp ASSR快捷可靠,较调制声ASSR能更好地评估感音神经性聋成人的听力。     

Steady-state response audiometry in a group of patients with steeply sloping sensorineural hearing loss

OBJECTIVES: The purpose of this study was to examine the predictive value of auditory steady-state response (ASSR) evoked potential thresholds and predicted behavioral thresholds in a group of children with steeply sloping sensorineural hearing loss (HL). STUDY DESIGN: Case series. METHODS: Twenty-nine children with sloping sensorineural HL underwent behavioral audiometric evaluation, impedance testing, distortion product otoacoustic emissions, and steady-state response testing. A t test was performed to compare the means of ASSR predicted behavioral thresholds and behavioral responses. Pearson correlation coefficients were calculated at each tested frequency, 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz, using the same data. RESULTS: Bracketed thresholds were obtained at 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz. Nineteen ears were used in this evaluation. A comparison of threshold difference as a function of bracketing revealed that the means were statistically different (P < .05). The mean threshold differences were calculated, and Pearson r values were determined between the behavioral thresholds and the predicted thresholds using the Rance 95 algorithm. The results revealed no difference of means at 500 Hz between predicted and measured behavioral thresholds. Linear regression analysis revealed strong correlation at 500 Hz, 1,000 Hz, and 2,000 Hz. CONCLUSIONS: The GSI Audera appears to predict the configuration of HL in children with steeply sloping sensorineural HLs and over-predicts the severity of the loss by 15 to 20 dB above 500 Hz at each test frequency (1,000, 2,000, and 4,000 Hz). Correlation coefficients display a strong correlation at 500 Hz, 1,000 Hz, and 2,000 Hz.