The effects of crossed olivocochlear bundle section on transient evoked otoacoustic emissions

The purpose of this study was to investigate the effect of sectioning the crossed olivocochlear bundle (COCB) on transient evoked otoacoustic emissions (TEOAEs) in anesthetized adult chinchillas. Of particular interest is the role of cochlear efferents to the outer haircells (OHCs) and how they control mechanisms responsible for otoacoustic emissions. Specifically the experiment addressed whether a tonic level of inhibitory control is reduced by COCB section. The nonlinear component of TEOAEs was measured before and after COCB section. Analysis was made of the 1, 2, 3, 4, and 5 kHz frequency components and of the total emission, as quantified by fast Fourier transform (FFT) of the raw (time domain) response. After COCB section, the amplitude of the total response and of the 2, 3, 4, and 5 kHz components increased whereas the amplitude of the 1 kHz component decreased. The results indicate that COCB section reduces inhibitory control of the OHC mechanisms responsible for nonlinear TEOAE generation. It is not clear whether the nerve section eliminates a spontaneous level of activity in COCB efferents, or whether it results in the interruption of a stimulus-evoked feedback loop.     

Effects of interaural intensity and time disparity on transient evoked otoacoustic emissions

Monaural and binaural 11/s, 65 dB pe SPL clicks with interaural time and intensity disparities known to affect central auditory processing were used to study contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) in 10 subjects (20 ears). Psychophysical assessment of sound lateralization induced by the same stimuli was also conducted. TEOAEs were recorded to monaural (ipsilateral to the OAE recording probe) and to binaural clicks when clicks to the contralateral ear were synchronous and symmetrical in intensity, or, in the binaural intensity disparity conditions, synchronous but 10 dB higher or 10 dB lower in the ear contralateral to the OAE recording probe. When interaural time disparities were studied, the clicks to the contralateral ear were of the same intensity throughout, but 400 μs earlier or 400 μs later than to the ear with the probe. The TEOAE components at 13–15.8 ms showed suppression, relative to monaural responses, under all binaural conditions. This contralateral suppression did not correlate with the psychophysical findings. Suppression effects were more pronounced with binaural disparity than with binaurally symmetrical clicks. Thus, although contralateral click intensity was the same with time disparities, suppression was paradoxically enhanced compared to the binaurally symmetrical stimulation. To explain these results we propose that two factors are involved in TEOAE suppression with binaural clicks: (1) contralateral intensity and (2) interaural disparity (time or intensity). The latency of the suppressions observed, the effect of interaural disparity on these suppressions, coupled with the anatomical origin of the crossed efferent fibers and the disparity sensitivity of the superior olivary complex (SOC), all suggest SOC involvement in these TEOAE suppressions.     

TEOAE suppression in adults with learning disabilities

The presentation of contralateral noise during the recording of transient evoked otoacoustic emissions (TEOAEs) reduces the amplitude of the TEOAE in normally-hearing adults. This is known as TEOAE suppression. The present study investigated TEOAE suppression in 18 adults with learning disabilities (LDs) compared to 18 adults without LDs. TEOAEs were elicited by 60 dB p.e. SPL clicks and were suppressed by the presentation of 60 dB SPL contralateral broadband noise. Suppression was measured as a change in the overall TEOAE response amplitude, and also analysed in 2-ms epochs representing different TEOAE frequency-response bands. A significant interaction was evident between group type and ear tested. Participants in the control group had right ear dominance for the suppression effect, whereas the left ear was found to be dominant for the LD group. These findings suggest a mechanism of the medial olivary cochlear bundle and efferent auditory pathway that differs in those with LD compared to those with typical learning abilities.     

Investigation of hearing aid users' speech understanding in noise and their spectral-temporal resolution skills

PurposeOur study aims to compare speech understanding in noise and spectral- temporal resolution skills with regard to the degree of hearing loss, age, hearing aid use experience and gender of hearing aid users.MethodsOur study included sixty-eight hearing aid users aged between 40-70 years, with bilateral mild and moderate symmetrical sensorineural hearing loss. Random gap detection test, Turkish matrix test and spectral-temporally modulated ripple test were implemented on the participants with bilateral hearing aids. The test results acquired were compared statistically according to different variables and the correlations were examined.ResultsNo statistically significant differences were observed for speech-in-noise recognition, spectral-temporal resolution among older and younger adults in hearing aid users (p>0.05). There wasn’t found a statistically significant difference among test outcomes as regards different hearing loss degrees (p>0.05). Higher performances were obtained in terms of temporal resolution in male participants and participants with more hearing aid use experience (p<0.05). Significant correlations were obtained between the results of speech-in-noise recognition, temporal resolution and spectral resolution tests performed with hearing aids (p<0.05).ConclusionOur study findings emphasized the importance of regular hearing aid use and it showed that some auditory skills can be improved with hearing aids. Observation of correlations among the speech-in-noise recognition, temporal resolution and spectral resolution tests have revealed that these skills should be evaluated as a whole to maximize the patient's communication abilities.     

对侧抑制对噪声暴露后的瞬态诱发耳声发射的影响

目的 :了解对侧抑制对噪声暴露前后瞬态耳声发射 (TEOAE)的影响。方法 :观察对侧抑制 (6 0dBSPL宽带噪声 )对噪声暴露前后TEOAE反应幅值、波重复率、频带信噪比、频带重复率等指标的变化。结果 :短时噪声暴露后 ,TEOAE各指标的数值都有所下降 ,敏感地反映出噪声暴露对耳蜗功能的影响。对侧抑制在噪声暴露前可引起较小的下降 ,部分指标有显著性改变。暴露后 ,对侧抑制使TEOAE指标下降更明显。结论 :噪声暴露可对耳蜗功能状态产生明显影响 ,降低耳声发射的测值。对侧抑制对耳蜗进行负反馈调节 ,可明显提高TEOAE测试检出噪声暴露所引起改变的敏感度。     

Learning effect observed for the speech reception threshold in interrupted noise with normal hearing listeners

Traditionally, the speech reception threshold (SRT) for sentences in noise is measured in stationary speech-shaped noise; however, non-stationary masking noises are gradually becoming more common. A previous study by Rhebergen et al. () suggested that a learning effect might be present for the SRT in interrupted noise but not in stationary noise. The current study tested if a stable SRT for female or male speech is reached by determining SRTs in listeners with normal hearing in either stationary or 8-Hz interrupted noise after five replications. Contrary to repeated SRT measurements in stationary noise, a significant improvement was observed for SRTs in interrupted noise with replication. For both speech materials, after five replications, the SRT in interrupted noise improved about 3 to 4 dB in comparison to the first SRT. Stable thresholds seem to be reached after about two replications. This experiment shows that there is a substantial learning effect present in SRT measurements with interrupted noise but not in stationary noise. With non-stationary noise, it is recommended to include a repeated measures design.     

An implementation study of neonatal hearing screening in the Netherlands

The objective of this study was to investigate whether universal neonatal hearing screening could be integrated in the youth health care program. The screening was performed by nurses of the well baby clinics. A three stage transient evoked otoacoustic emission screening was performed in three different screening settings in order to study the most effective set up regarding participation, refer rates, and costs. In one setting parents visited the well baby clinic, and in two settings babies were screened at home (either in combination with the screening for metabolic diseases or during an intake visit). Screening was performed on 3114 healthy newborns. The setting where universal neonatal hearing screening is integrated with the screening for metabolic diseases, proved to be most efficient and effective. The participation rate of 88.9% was highest in this setting and the overall refer rate (1.4%) was the lowest. The implementation of universal neonatal hearing screening by the well baby clinic nurses was judged to be possible. The results of this study formed the basis for nationwide implementation.     

Maturation of the auditory system: 2. Transient otoacoustic emission suppression as an index of the medial olivocochlear bundle maturation

Contralateral suppression of transient otoacoustic emissions in 42 premature babies (84 ears; post-conceptional age [PCA] 30–36 weeks) was compared to that of 39 full-term babies (78 ears; PCA: 37–45 weeks). Eighteen healthy adults and ten young children (5–14 years old) were studied as controls. Risk factors for hearing loss were registered in both preterm and full-term groups. An ILO–92 otoacoustic emission recording system was used to deliver linear clicks to the ear examined and broadband noise to the contralateral ear in an alternating on and off mode.

Suppression in full-term babies was statistically higher than in preterms, whereas no differences existed between children and adults and children and full-terms. Peripheral auditory lateralization was evident in adults but was observed only as a trend in newborns. Only prematurity at the time of examination and aminoglycoside treatment for more than seven days had a negative impact on suppression.

The results support the conclusion that maturation of the efferent system takes place from 30 to 45 weeks PCA. The exact age at which this maturation is accomplished has not yet been clearly determined.     

睡眠质量对听力正常青年人DPOAE和噪声下言语识别的影响

目的 初步研究睡眠质量对听力正常青年人DPOAE和噪声下言语识别的影响.方法 将50例听力正常在校大学生根据匹兹堡睡眠质量指数量表(Pittsburgh sleep qualily index,PSQI)评分分为睡眠质量较差组(PSQI评分≥7分,25例)和睡眠质量较好组(PSQI评分<7分,25例),对两组进行DPO...     

不同环境对正常青年人诱发性耳声发射检测的影响

目的 研究正常青年人在隔音和非隔音环境下的瞬态诱发耳声发射（TEOAE）和畸变产物耳声发射（DPOAE）,探讨环境噪声对耳声发射的影响,为临床应用提供参考。方法 应用Capella耳声发射仪对正常听力青年人102耳分别在隔音和非隔音环境下记录DPOAE和TEOAE。结果 两种环境下DPOAE的幅值无显著差异,信噪比（S/N－ratio）、叠加次数、扫描时间有显著性差异;ＴＥＯＡＥ的幅值、信噪比、相关系数（Ｃorr)、叠加次数、扫描时间均有显著性差异;隔音和非隔音环境下的ＤＰＯＡＥ、ＴＥＯＡＥ的通过率有显著性差异。结论 环境噪声（５５－６５dBSpL)对ＤＰＯＡＥ幅值（除０.5kHz外）无明显影响,对ＴＥＯＡＥ有显著影响;在听力筛选时,尤其是在非隔音环境下应用ＤＰＯＡＥ较ＴＥＯＡＥ准确率高;不但具有频率特异性,且可明显降低假阳性率。     

Effects of speech signal content and speaker gender on acceptance of noise in listeners with normal hearing

Abstract

Objective: The purpose of this research was to determine if the content and/or speaker gender of a running speech sample affected the acceptance of background noise within a participant. Design: A male and a female recording of the Arizona Travelogue (Cosmos Inc.) and the ipsilateral competing message (ICM) from the synthetic sentence identification with ICM were created and used as the experimental speech signals. Two acceptable noise level measurements were obtained and averaged for each condition. Twenty-one participants rated interest level in the speech sample for each condition. Study Sample: Forty-three listeners with normal hearing participated. Results: Interest level was significantly greater for the ICM than the Arizona Travelogue speech samples, and was significantly greater for female samples. Neither the content of the sample nor the gender of the speaker significantly affected the most comfortable level or the acceptable noise level. Conclusions: Findings suggest that the acceptable noise level can be measured using various types of speech signals for normal-hearing listeners.

Sumario

Objetivo: El propósito de esta investigación fue determinar si el contenido y/o el género del locutor en una muestra de lenguaje corrido afectaba la aceptación del ruido de fondo en un mismo participante. Diseño: Se realizóuna grabación con la participación de un hombre y una mujer del Arizona Travelogue (Cosmos Inc.) y del Mensaje Competitivo Ipsilateral (ICM) de la prueba de identificación de Frases Sintéticas con ICM, y se creó una material que fue utilizado como señal lingûstica experimental. Se obtuvieron dos mediciones de niveles de ruido aceptables y se promediaron para cada condición. Veintiún participantes calificaron el nivel de interés de la muestra de lenguaje para cada condición. Muestra del Estudio: Participaron cuarenta y tres sujetos con audición normal. Resultados: El nivel de interés fue significativamente mayor para las muestras de lenguaje del ICM que para las del Arizona Travelogue y estas fueron significativamente mayores para muestras grabadas por mujeres. Ni el contenido de la muestra ni el género del locutor afectó significativamente el nivel más confortable o el nivel aceptable de ruido. Conclusiones: Los hallazgos sugieren que el nivel aceptable de ruido puede medirse usando varios tipos de señales de lenguaje para oyentes con audición normal.     

Evaluation of cochlear involvement by transient evoked otoacoustic emission test in children with Crimean-Congo hemorrhagic fever

Objective

The aim of this study was to investigate cochlear involvement in child patients with Crimean-Congo hemorrhagic fever (CCHF) disease.

Methods

Twenty-eight CCHF disease patients (56 ears) and 26 sex- and age-matched healthy control subjects (52 ears) were included in the study. Pure-tone audiometry at frequencies 0.25, 0.5, 1, 2, 4, and 6 kHz, immittance measures including tympanometry and acoustic reflex testing, and transient evoked otoacoustic emission (TEOAE) testing were performed in the patients and controls.

Results

The proportion with a result of ‘fail’ for the TEOAE test in the CCHF patients was not statistically significant from the control group (p > 0.05).

Conclusions

CCHF disease does not impair cochlear function in children. The clinical course of CCHF among children seems to be milder than in adults.     

自闭症患儿的听功能及其传出神经功能评估

目的评估自闭症患儿的听功能和传出神经功能。方法对30例自闭症患儿和15例正常儿童分别行听性脑干反应（ABR）和耳声发射（OAE）测试,并以55dBnHL白噪声为对侧抑制声,进行畸变产物耳声发射（DPOAE）和瞬态诱发耳声发射（TEOAE）对侧抑制效应测试,比较两组结果。结果①ABR检查结果：30例（60耳）自闭症患儿中,25例（50耳）的ABR闯值均在20dBnHL以内,1例左耳闽值为30dBnHL,右耳阉值为40dBnHL,1例（2耳）阈值均为50dBnHL,3例（6耳）ABR未引出;正常组15例（30耳）ABR阈值均在20dBnHL以内;与正常组左、右耳I-V波间期（分别为4．30&#177;0．14、4．31&#177;0．14ms）比较．自闭症组（分别为4．07&#177;0．24、4．08&#177;0．22ms）有缩短的趋势（P〈O．05）;②OAE检查结果：正常组均可引出;30例自闭症患儿除3例ABR未引出者和1例双耳ABR阈值为50dBnHL者OAE未引出外,其余26例均引出,且1、2kHzOAE幅值与正常组差异有统计学意义（P〈0．05）;③对侧抑制结果：正常组幅值均降低;自闭症组26例OAE可引出者中,1例ABR阂值不对称者对侧给予55dBnHL白噪声后,OAE幅值不降低反而升高,其余25例OAE幅值均降低;两组OAE对侧抑制幅值差值无统计学差异。结论与同龄正常儿童相比,自闭症患儿更容易出现听功能障碍。     

Auditory event-related potentials and function of the medial olivocochlear efferent system in children with auditory processing disorders

Objective: The objectives were to investigate the function of central auditory pathways and of the medial efferent olivocochlear system (MOCS).

Design: Event-related potentials (ERP) were recorded following the delivery of the stimulus /da/ in quiet and in ipsilateral, contralateral, and binaural noise conditions and correlated to the results of the auditory processing disorders (APD) diagnostic test battery. MOCS function was investigated by adding ipsilateral, contralateral, and binaural noise to transient evoked otoacoustic emission recordings. Auditory brainstem responses and pure tone audiogram were also evaluated.

Study Sample: Nineteen children (7 to 12?years old) with APD were compared with 24 age-matched controls.

Results: Otoacoustic emissions and ABR characteristics did not differ between groups, whereas ERP latencies were significantly longer and of higher amplitudes in APD children than in controls, in both quiet and noise conditions. The MOCS suppression was higher in APD children.

Conclusions: Findings indicate that children with APD present with neural deficiencies in both challenging and nonchallenging environments with an increase in the timing of several central auditory processes correlated to their behavioural performances. Meanwhile, their modulation of the auditory periphery under noisy conditions differs from control children with higher suppression.     

Influence of noise exposure on antioxidant system and TEOAEs in rabbits

Noise exposure may cause hearing loss. The precise mechanism leading to cochlear damage in acoustic trauma is not known. Eight rabbits were used in this study. Transient evoked otoacoustic emissions (TEOAEs) were recorded in all animals and blood malondialdehyde (MDA) and glutathione (GSH) levels were determined. All rabbits were then exposed to 100 dB SPL broadband noise for 1 h. TEOAEs were recorded again and blood MDA and GSH levels determined following noise exposure. The reproducibility scores of the TEOAE measurements were found to be significantly lower (P < 0.01), whereas the amplitudes and signal-to-noise values of emissions decreased (P > 0.01) in rabbits exposed to noise. The TEOAE energies were poor at 4 kHz. During this threshold shift, GSH blood levels decreased and MDA levels increased, indicating that there is a close relationship between noise-induced hearing loss and the antioxidant system. These findings indicate that TEOAE recording is an excellent test for detecting effects of noise on hearing. Received: 29 September 2000 / Accepted: 15 June 2001     

Speech perception in noise for bilingual listeners with normal hearing

Objective: The purpose of this study was to determine if speech-in-noise ability, as measured by SNR-50 and SNR loss in bilingual Spanish listeners with normal hearing, was affected by test difficulty. Design: Quasi-experimental, non-randomized intervention study. Study sample: Two groups of adult listeners participated: monolingual English listeners with normal hearing (N?=?12) and bilingual Spanish listeners with normal hearing who were proficient in English (N?=?10). The quick speech-in-noise (QuickSIN), the Bamford-Kowal-Bench speech-in-noise (BKB-SIN), and the words-in-noise (WIN) tests were used to assess signal-to-noise ratio (SNR) loss and SNR-50 for both groups. Results: Despite the fact that the bilinguals had normal hearing and were proficient in English, each of the speech-in-noise tests evaluated indicated the Spanish listeners had measurable SNR loss and higher than normal SNR-50s. Performance on the BKB-SIN was best for both groups, indicating test difficulty had a significant impact on speech perception in noise. Conclusions: Bilingual Spanish listeners with normal hearing exhibited a mild SNR loss comparable to that observed for a person with hearing loss. This decreased performance in noise requires an improved SNR for this population to reach a comparable level of comprehension to their monolingual English counterparts.     

The interaction of hearing loss and level-dependent hearing protection on speech recognition in noise

Abstract

Objectives: To determine the effects of different control settings of level-dependent hearing protectors on speech recognition performance in interaction with hearing loss. Design: Controlled laboratory experiment with two level-dependent devices (Peltor^® PowerCom Plus? and Nacre QuietPro^®) in two military noises. Study sample: Word recognition scores were collected in protected and unprotected conditions for 45 participants grouped into four hearing profile categories ranging from within normal limits to moderate-to-severe hearing loss. Results: When the level-dependent mode was switched off to simulate conventional hearing protection, there were large differences across hearing profile categories regarding the effects of wearing the devices on speech recognition in noise; participants with normal hearing showed little effect while participants in the most hearing-impaired category showed large decrements in scores compared to unprotected listening. Activating the level-dependent mode of the devices produced large speech recognition benefits over the passive mode at both low and high gain pass-through settings. The category of participants with the most impaired hearing benefitted the most from the level-dependent mode. Conclusions: The findings indicate that level-dependent hearing protection circuitry can provide substantial benefits in speech recognition performance in noise, compared to conventional passive protection, for individuals covering a wide range of hearing losses.     

瞬态诱发耳声发射甘油试验对初次发作眩晕的诊断价值

目的：探讨瞬态诱发耳声发射（TEOAE）甘油试验对初次发作眩晕的诊断价值。方法：对28例眩晕初次发作,纯音听阈（PTT）正常,无耳鸣及耳胀满感,病史及临床特征不支持非梅尼埃病的眩晕患者进行PTT及TEOAE甘油试验。结果：28例中,4例服甘油后PTT及TEOAE均无改变,其各项观察值在正常范围;TEOAE甘油试验阳性20例（单耳16例,双耳4例）,其中2例（2耳）服甘油前TEOAE未引出,服甘油后可引出,TEOAE甘油试验阳性耳,服甘油前、后TEOAE各观察值均低于正常人标准;4例PTT甘油试验阳性,但服甘油前后TEOAE均未引出。结论：TEOAE甘油试验可作为将首次发作眩晕而听力正常患者早期诊断为梅尼埃病及鉴别诊断的常规方法。