Contralateral suppression of otoacoustic emissions in neonates

The effect of contralateral acoustic stimulation on transient evoked otoacoustic emissions (TEOAEs) was used to investigate the activity of the medial olivocochlear bundle in neonates. TEOAEs were bilaterally recorded, with and without contralateral noise, in 120 full-term neonates without risk for hearing loss. Otoacoustic emission recordings were carried out using the Otodynamic ILO88 system quickscreener non-linear mode, and the contralateral stimulation was presented at 60 dB SPL delivered by CD player. The results revealed a significant (p<0.01) contralateral suppression of TEOAE response amplitude: 2.32 dB in females and 3.28 dB in males. This study shows that the suppression effect is present in 88.5% of neonates, with a gender difference (greater suppression in males) and frequency effect, suggesting a functional maturation of the medial olivocochlear bundle in the studied population.     

Contralateral suppression of transient evoked otoacoustic emissions in children with auditory processing disorder

This study concerns contralateral white noise suppression of transient evoked otoacoustic emissions (TEOAEs) in children with auditory processing disorder (APD). Fifty-one children between 7 and 11 years were assigned to 1 of 3 experimental groups: those without auditory complaints (n = 15), those with APD who scored high on a standardized test (n = 20) and those with APD who scored lower on the same test (n = 16). For all groups TEOAE suppression was determined in both linear and nonlinear acquisition mode. The results provide evidence that abnormal TEOAE suppression was significantly more common in the APD groups than in the control group. Contralateral suppression of TEOAE is an additional tool for assessing the efferent pathway in children with APD.     

Contralateral suppression of transient evoked otoacoustic emissions in patients with cerebello-pontine angle tumor.

OBJECTIVE: During measurement of transient evoked otoacoustic emissions (TEOAEs), acoustic stimulation of the contralateral ear reduces or suppresses TEOAE amplitude. This is thought to be due to the inhibitory control that the medial efferent auditory nerve exerts on outer hair cell (OHC) function. The main aim of this study was to investigate the effect of cerebello-pontine angle (CPA) tumor on the medial efferent nerve pathways to both tumor and non-tumor ears by examining alterations in TEOAE amplitude that result from contralateral acoustic stimulation. DESIGN: Contralateral suppression of TEOAEs using broadband noise was measured preoperatively in 17 patients with unilateral CPA tumor and 17 normally hearing controls, matched for age and gender. RESULTS: The control ears demonstrated significantly more suppression than the tumor and non-tumor ears in the patient group. There was, however, no significant difference in suppression between the tumor and non-tumor ears, and the statistical correlation for suppression between them was high. There was no effect of gender, hearing threshold levels, or size and type of tumor on suppression, although there was an effect of age on suppression in both the control and patient groups where suppression reduced as age increased. Four of the 17 patients had TEOAEs, which were clearly present in the tumor ear despite substantial hearing loss, three of which had no measurable hearing. CONCLUSIONS: It is hypothesized that neural compression by CPA tumor disrupts the medial efferent nerve control mechanism to the OHCs of tumor ears. It also is hypothesized that neural compression reduces transmission of afferent nerve impulses from the tumor ear, which cross over to the medial olivo-cochlear complex and reduce the inhibitory control of OHC function in the non-tumor cochlea.     

糖尿病患者瞬态诱发耳声发射对侧抑制现象的临床研究

目的:研究听力正常的糖尿病患者瞬态诱发耳声发射(TEOAE)对侧抑制现象.方法:分别对30例听力正常的糖尿病患者(糖尿病组)及30例健康对照者(对照组)行纯音听阈、声导抗、TEOAE检测,并通过在其对侧耳中加入60 dB SPL的宽带噪声后TEOAE对侧抑制效应测试以评估其传出神经功能.结果:糖尿病组受试者的纯音听阈及TEOAE的幅值稍低于对照组,但两者间差异无统计学意义;其TEOAE的对侧抑制效应低于对照组,其中在2000 Hz及4 000 Hz处差异有统计学意义(P<0.05).结论:糖尿病患者在其外周听力尚处于正常状态时,其听觉传出神经的功能即已发生了改变.     

Aging and contralateral suppression effects on transient evoked otoacoustic emissions

Transient evoked otoacoustic emissions (TEOAEs) were recorded in 30 normal-hearing subjects to nonlinear clicks while continuous contralateral broadband noise (CBBN) was presented at 40, 50, 60, and 70 dB HL. Thirty subjects between 20 and 79 years were divided system-atically into six-decade age groups, five subjects per group. All subjects in each group had hearing thresholds of 20 dB HL or better for the test frequencies from 0.25 to 8.0 kHz and normal acoustic immittance findings. The results provide evidence that contralateral suppression at varying levels of CBBN is interactive with age. Except for subjects in the age ranges between 60 and 69 and 70 and 79 years of age, an increase in CBBN from 40 to 70 dB in 10-dB steps resulted in an average increase in suppression from about 0.5 to 3.5 dB SPL. In addition, the contralateral suppression at 60 and 70 dB HL was significantly greater for subjects between 20 and 59 years of age than for subjects between 60 and 79 years of age.     

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.     

Identification of hearing loss in newborns by transient otoacoustic emissions

OBJECTIVE: More than 90% of congenital hearing loss cases are of cochlear origin. There are two methods for newborn hearing screening: the transient otoacoustic emission (TEOAE) or (ABR) screening. When TEOAE is used for hearing screening patients, newborn with a neural hearing loss are not discovered. MATERIALS: In the present study TEOAEs were obtained from 3,048 newborns from both ears in patients with and without risk factors for hearing loss in the history. All newborns who did not pass TEOAE in the 2nd screening (uni or bilaterally) underwent additional audiologic tests. RESULTS: In the first screening 150 (4.5%) of the newborns newborn did not pass the screening and 30 (0.98%) did not pass in the second screening. In nine newborns with unilateral absent TEOAE and in two newborns a deafness was confirmed, with one side cochlear and on the other side retrocochlear. Both patients received cochlear implants before the 2nd year of age. In 21 newborns with absent TEOAE bilaterally, five had moderate sensorineural hearing loss bilaterally and in nine patients profound hearing loss (90-100 dB) or deafness was confirmed. Of 3,048 newborns there were 1,355 with a risk of hearing loss and in 12 (0.88%) newborns bilateral hearing loss or deafness was confirmed; of the 1663 newborns without risk of hearing loss in the history, in four (0.24%) newborn deafness or bilateral sensorineural hearing loss in the range of 45-65 dB were confirmed. CONCLUSION: When the newborn has an absent TEOAE uni or bilaterally, we need to inform the parents and to recommend additional screening and other audiologic tests to confirm or exclude hearing loss.     

Effect of smoking on transient evoked otoacoustic emissions and contralateral suppression

Objective

The present study compared the amplitudes of transient evoked otoacoustic emissions (TEOAEs) and efferent suppression in smokers and non-smokers taking age into consideration.

Methods

Fifty smokers and fifty non-smokers who had normal hearing sensitivity with age range of 20–69 years were considered for the present study. TEOAEs were measured in both the groups of subjects across different age groups. The functioning of the efferent auditory system was evaluated in both the groups by recording the TEOAEs in the presence of a contralateral white noise (CWN) of 70 dB SPL.

Results

Age did not have a significant effect on the TEOAEs amplitude in both the groups of subjects. However, the TEOAEs amplitude was significantly reduced in smokers compared to non-smokers. The results found a significant effect of age on the amplitude of efferent suppression in smokers, however, no significant effect was found in the non-smokers group.

Conclusions

It was found that the difference in the amplitude of efferent suppression in smokers was significantly greater for each age group between 20 and 49 years compared to each age group from 50 to 69 years. Results have important implication on the damage to the cochlear structures from smoking.     

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。     

足月新生儿瞬态诱发性耳声发射能量谱分析

本文对115例足月新生儿,230耳,以瞬态诱发性耳声发射的快速筛查方法进行测试。分析500～5657Hz的各半倍频程的反应和噪声的能量谱,结果显示反应能量和检出率最高的四个频带为1 414Hz、2 000Hz、2 828Hz、4 000Hz,检出率最低的频带为500Hz与707Hz,反应能量最低的三个频带为5 657Hz、707Hz和500Hz;噪声水平最高的三个频带依次为500Hz、1000Hz与707Hz。左右耳的反应能量在1 000Hz、1 414Hz、2 000Hz与2 828Hz等频带有显著性差异。除2 000Hz外,各频带反应能量不存在性别差异。     

Neonatal hearing screening with transient evoked otoacoustic emissions in Western Saudi Arabia

OBJECTIVE: To study the incidence of congenital hearing impairment in the Saudi population and to evaluate the need of establishing a Saudi universal neonatal hearing screening program based on transient evoked otoacoustic emission. METHODS: A total of 11986 well non-high-risk neonates were screened by transient evoked otoacoustic emission over period of 8 years from September 1996 to February 2004. The universal hearing screening was consequently done in a daily base before discharge from nursery. Those who failed the initial screening were followed up diagnostically until hearing loss was confirmed or excluded. RESULTS: From the total number of 11,986 neonates (41.4% male and 58.6% females) examined in this study 10943 (91.3%) neonates passed the first screening step while 1043(8.7%) neonates failed. From the 1043 neonates examined in the second screening step in the 5th day of life, 300 (29%) neonates failed. At the age of 5 months, all the 300 infants that failed the second screening step underwent a comprehensive audiological assessment to confirm the existence of hearing loss. The 278 infants that passed the assessment were considered as normal; while 22 failed and were confirmed to have congenital hearing loss. Of these 22 infants, 2 had unilateral sensorineural hearing loss, and the remaining 20 had bilateral sensorineural hearing loss. The incidence of sensorineural hearing loss was estimated to be 0.18% while the incidence of bilateral sensorineural hearing loss was 0.17%. No significant difference between males and females was found. The average age at confirmation of congenital hearing loss was 5.5 months. CONCLUSION: The incidence of congenital hearing loss in the western region of Saudi Arabia is relatively high compared with international figures. Hearing screening for all neonates using transient evoked otoacoustic emission should be part of the standard medical care in Saudi Arabia.     

新生儿自发性耳声发射与瞬态诱发性耳声发射的相关性

目的分析自发性耳声发射（spontaneous otoacoustic emission,SOAE）与瞬态诱发性耳声发射（transient evoked otoacoustic emission,TEOAE）之间的相关性。方法新生儿112例（224耳）,其中女59例,男53例,出生后2～4天内行SOAE及TEOAE检测。结果每耳SOAE信号峰数量与其TEOAE强度相关（r=0.43,P〈0.001）。每耳最大SOAE波幅与其TEOAE强度相关（r=0.49,P〈0.001）。不同耳依据其SOAE信号峰数量将其分为4组：I组无SOAE信号峰;II组为单SOAE信号峰;III组为2～3个SOAE信号峰;IV组为3个以上信号峰。I组TEOAE强度为（10.96±3.77）dBSPL,II组（12.87±3.27）dBSPL,III组（15.61±3.23）dBSPL,IV组（17.100±4.51）dBSPL,各组间的TEOAE强度差异均具有统计学意义。II组SOAE最大强度（-13.54±9.21）dBSPL,III组（-4.56±7.22）dBSPL,IV组（1.00±7.35）dBSPL,各组间最大SOAE波幅差异具有统计学意义。结论SOAE信号峰数量、最大SOAE波幅与TEOAE强度之间存在正相关关系,SOAE信号峰越多,最大SOAE波幅也越强,同时TEOAE强度也越强。     

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.     

Frequency-specific information from click evoked otoacoustic emissions in noise-induced hearing loss.

Click evoked otoacoustic emissions (CEOAEs), pure-tone audiograms (PTAs), and Bekesy sweep frequency audiograms were recorded from 15 ears of 11 subjects with noise-induced hearing loss. For all ears, hearing threshold levels > or = 30 dB HL were found at the high frequencies. The aims of the study were to examine whether the decomposition of CEOAEs into narrow band components could identify hearing loss in a frequency-specific manner and to what extent audiometric thresholds could be predicted. CEOAEs were parcelled into 0.5-kHz-wide components by means of the wavelet transform. Reproducibility of CEOAE components was compared with audiometric threshold at corresponding frequencies. A general trend of low reproducibility for increasing audiometric thresholds was found. A reproducibility value of 60 per cent was found to best separate normal and elevated thresholds. The presence of a CEOAE component at a given frequency was always associated with audiometric thresholds < or = 20-25 dB HL. On the other hand, the absence of a component was equally associated either with normal or abnormal hearing levels. Large inter-subject variability was observed. A weak linear relationship was found between reproducibility and audiometric thresholds at corresponding frequencies, indicating that analysis of narrow band CEOAE components is valuable for separating normal from hearing-impaired ears but cannot replace the audiogram.     

Neonatal hearing screening with transient evoked otoacoustic emissions: a learning curve

The present paper reports on the implementation of a neonatal hearing screening programme in a private hospital in Belgium. A maternity-based neonatal hearing screening project with transient evoked otoacoustic emissions (TEOAEs) was started in 1993. The cost of the test was not covered by the public health insurance, so the parents had to pay the full cost for screening their child (approximately 30 Euro). Since 1993 the programme strategies have been changed on several occasions to improve the quality and efficacy. A retrospective analysis was performed on: (1) the test pass rate; (2) the coverage; and (3) the number of children who become 'Lost to follow-up' after failing the initial test. The data show a steady learning curve with a time course of several years. They also demonstrate that it is worthwhile and feasible to run a high-quality screening programme in a private establishment.