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.     

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.     

Otoacoustic emissions in full-term newborns at risk for hearing loss

Distortion product otoacoustic emissions (DPOEs) and click-evoked otoacoustic emissions (CEOEs) characteristics of the normal newborn population have been previously reported in the literature. There is little information about DPOE evaluations in the newborn population at risk for hearing loss. The authors now report the DPOE and/or CEOE data from six full-term subjects at risk for hearing loss or with highly suspected hearing loss. These subjects were less than 1 year of age and at risk for hearing loss secondary to a history of hereditary hearing loss, meningitis, hyperbilirubinemia, and ototoxic drug exposure. Audiometric evaluation included auditory brainstem responses (ABR), behavioral observation audiometry, and tympanometry. The CEOEs and DPOEs were found to be decreased or absent in the subjects with suspected hearing loss secondary to cochlear pathology; they were found to be normal in a subject with a suspected central hearing loss. This study's data suggest that otoacoustic emissions when combined with ABR can provide a frequency-specific evaluation of cochlear function and help determine the anatomic site of a pathologic lesion.     

Otoacoustic emissions screening as early identification of hearing loss in newborns

The aim of this study was to examine the results of transient evoked otoacoustic emissions (TEOAE) as screening test for hearing impairment in newborn infants. We examined 9.951 of 11.405 infants born in our city from January 1st, 1995, to December 31st, 1998. A TEOAE test was performed prior to discharge and repeated one week later in cases who failed the first TEOAE. In case of suspected hearing loss auditory brainstem response (ABR) was performed 3 months later. Hearing loss was defined as ABR threshold > 20 dB. 157 infants (1.5%) were identified with hearing loss. Screening with TEOAE was sufficiently sensitive in identification of congenital hearing impairment and the efficacy increased with the experience.     

耳声发射应用于新生儿听力筛选的研究

目的 研究瞬态诱发耳声发射（ｔｒａｎｓｉｅｎｔ ｅｖｏｋｅｄ ｏｔｏａｃｏｕｓｔｉｃ ｅｍｉｓｓｉｏｎｓ,ＴＥＯＡＥ）产畸变产物耳声发射（ｄｉｓｔｏｒｔｉｏｎ ｐｒｏｄｕｃｔ ｏｔｏａｃｏｕｓｔｉｃ ｅｍｉｓｓｉｏｎｓ,ＤＰＯＡＥ）应用于新生儿听力筛选的可行性,控诉听力筛选的标准。方法 应用Ｃｅｌｅｓｔａ５０３型耳声发射分析仪对１０８名新生儿（２１６耳）进行ＴＥＯＡＥ和ＤＰＯＡＥ听力筛选,与听性脑     

Otoacoustic emissions and extended high-frequency hearing sensitivity in young adults

The relationship between hearing sensitivity in the extended high-frequency region (8-16 kHz) and (1) the presence of synchronized spontaneous otoacoustic emissions (SSOAEs) and (2) the strength of click-evoked and distortion product otoacoustic emissions (CEOAEs and DPOAEs) was investigated in 104 ears of 57 young adults. The age range was confined to 16 to 19 years. All subjects had normal hearing in the conventional audiometric frequency range (0.5-8 kHz). Ears with detected SSOAEs had better hearing sensitivity in the extended high-frequency region and also higher levels of CEOAEs and DPOAEs than ears with undetected SSOAEs. The results support the hypothesis that the presence of SSOAEs is indicative of an ear with highly normal cochlear function over a broad frequency range.     

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.     

耳声发射在重症监护新生儿听力筛查中的应用

目的 探讨重症监护新生儿(NICU)的合适听力筛查方法.方法 用瞬态诱发耳声发射仪(TEOAE),对263例重症监护新生儿进行听力筛查,未通过者1个月后进行复查,仍未通过者将接受脑干诱发电位(ABR)检查,以确定有无听力损失.结果 263例NICU新生儿中,209例通过了第一次OAE筛查,1个月后43例通过了OAE复查,最后11例行ABR检查,5例确诊有不同程度的听力损失.结论 TEOAE和 ABR联合应用的两步筛查法是NICU新生儿听力筛查的可行方法.     

Otoacoustic emissions in patients with hypotension

The aim of this study was to investigate the relation between hypotension and slowly developing hearing impairment, using otoacoustic emissions. A group of 42 patients was examined, with diastolic blood pressure < or = 60 mmHg and systolic blood pressure < or = 105 mmHg. The subjects underwent biochemical, cardiological, ENT and audiological examinations. Distortion product otoacoustic emissions (DPOAE) were recorded in the format of DP-gram. The results were compared to the data of 30 normal persons of similar age and sex, examined at the same laboratory. Audiometric results showed that 18 patients had mild or moderate symmetrical hearing loss in one or more frequencies, mainly in the lower frequency range. DPOAE of the patients had reduced amplitude as compared to controls or were even absent, in one or more frequencies. It may be concluded that a hypotensive condition could be a possible factor in the origin of cochlear damage and DPOAE may be useful in monitoring hypotensive patients.     

Directional hearing aid benefit in listeners with severe hearing loss

The purpose of this investigation was to examine the potential for directional hearing aid benefit in listeners with severe hearing loss at multiple SNRs for both auditory only and audio-visual presentation modes. Speech recognition performance was measured using the connected speech test at six SNRs individually determined for each subject in order to avoid floor and ceiling effects. The results revealed significant directional benefit was present at all tested SNRs in the presence of visual information. For auditory only presentations, significant directional benefit was only present at the least positive SNR. The largest directional benefit was measured at the poorest tested SNR for both auditory only and audiovisual presentation modes. The results of this study generally support small but significant directional for listeners with severe hearing loss benefit in a difficult listening environment both with and without the presence of visual information.     

Directional hearing aid benefit in listeners with severe hearing loss

The purpose of this investigation was to examine the potential for directional hearing aid benefit in listeners with severe hearing loss at multiple SNRs for both auditory only and audio-visual presentation modes. Speech recognition performance was measured using the connected speech test at six SNRs individually determined for each subject in order to avoid floor and ceiling effects. The results revealed significant directional benefit was present at all tested SNRs in the presence of visual information. For auditory only presentations, significant directional benefit was only present at the least positive SNR. The largest directional benefit was measured at the poorest tested SNR for both auditory only and audio-visual presentation modes. The results of this study generally support small but significant directional for listeners with severe hearing loss benefit in a difficult listening environment both with and without the presence of visual information.

Sumario

El objetivo de esta investigación fue examinar el beneficio potencial de los auxiliares auditivos direccionales en personas con hipoacusia severa en múltiples condiciones de señal/ruido (SNR) tanto en modo auditivo como en audio-visual. Se midió el desempeño en el reconocimiento del lenguaje mediante la prueba de lenguaje conectado a seis diferentes SNR, determinados en cada individuo para evitar el efecto de piso/techo. Los resultados revelan un beneficio direccional significativo en las seis condiciones de prueba en presencia de información visual. En la presentación exclusivamente auditiva, el beneficio sólo se presentó con la SNR menos positiva. El mayor beneficio direccional se midió con la SNR mas pobre tanto en el modo auditivo como en el audio-visual. Los resultados generales de este estudio apoyan que existe un beneficio direccional pequeño pero significativo para personas con hipoacusia severa en ambientes sonoros difíciles, con o sin información visual.     

Stimulated otoacoustic emissions in children with sensorineural hearing loss

Our previous studies of stimulated oto-acoustic emissions (OAEs) have revealed that the OAE threshold indicates the grade of inner ear impairment. The present study is a survey of OAE in children of school age. The mean OAE threshold values of 113 ears with normal hearing and 45 ears with functional deafness were 5.9 dB nHL and 6.2 dB nHL, respectively. In sensorineural loss the value was noted to increase according to its grade, classified into four groups, measuring 37.2 dB nHL in the group with severe loss higher than 91 dB. The findings suggest that the OAE threshold is useful for an indicator of inner ear function in children. There still remains the problem to be solved by a contrivance of noise removal for application of OAE to hearing tests in children of pre-school age.     

Otoacoustic emissions]

Spontaneous sound signals emitted from the inner ear were first recorded by Kumpf and Hoke in 1970. Kemp reported phenomena of sounds which were emitted by the ear responding to acoustic stimulation. These "otoacoustic emissions" are supposed to be generated in the outer hair cells. Active contractions of the actin and myosin in these cells produce a frequency specific cochlear amplifier mechanism. Although the clinical value of spontaneous otoacoustic emissions is yet unclear, as well as role in tinnitus, the recording of click-evoked otoacoustic emissions has now become diagnostic routine. Click-evoked otoacoustic emissions cannot be recorded in ears with cochlear mid-frequency hearing losses > or = 25 dB. However, the use of sinus tones or distortion products as stimuli promises more frequency-specific results. Most important for the quality of measurement is complete closure of the external ear canal, correct positioning of the recording probe, maximal suppression of background noise and sufficient compliance of the patient, especially when testing children. Middle ear effusions also prevent recording. Responses to a standard of 260 stimulations are averaged and identified as "true" emissions by their sufficient reproducibility and characteristic pattern in frequency analysis. Currently, the recording of click-evoked otoacoustic emissions can be used to detect early discrete lesions of the outer hair cells. Their use as a screening tool concerning cochlear hearing disorders is already possible in newborn children. Isolated central hearing disorders still cannot be detected by this diagnostic procedure.     

Otoacoustic emissions and tympanometry in a general adult population in Sweden

The present study concerns a general adult population in Sweden, not exposed to hazardous occupational noise. Tympanometry and spontaneous (SOAE), transient evoked (TEOAE) and distortion-product (DPOAE) otoacoustic emissions were investigated in 493 randomly selected men and women aged from 20 to 79 years. Effects of gender, age, ear side and middle ear state were determined, with and without adjusting for hearing threshold level. No statistically significant effects on middle ear pressure or compliance were present. For TEOAEs and DPOAEs, the effect of gender and age was statistically significant (p < 0.01), with larger signal levels for female subjects and young subjects, even after adjusting for hearing threshold level. No effect of middle ear pressure on otoacoustic emissions was present, but high middle ear compliance was associated with low emission levels (p < 0.01). Reference data for middle ear compliance and pressure and prevalence data on SOAEs, TEOAEs and DPOAEs for male and female subjects in different age groups were determined. Mean signal levels of TEOAEs and DPOAEs are presented.     

Occupational hearing loss: screening with distortion-product otoacoustic emissions

Hearing assessment of applicants for occupational hearing loss compensation can be a time-consuming process. An accurate screening procedure that is sensitive to occupational hearing loss may have application in many situations. The present study developed distortion-product otoacoustic emission (DPOAE) screening criteria to identify subjects likely to meet the Hong Kong requirements for occupational hearing loss compensation, namely a bilateral sensorineural loss ≥ 40 dB HL (average of 1000, 2000 and 3000 Hz). The screening criteria of 1500 and/ or 2000 Hz, with a signal-to-noise ratio of >0 or 3 dB, yielded high sensitivity and specificity. DPOAE measures therefore have the potential to accurately indicate possible occupational hearing loss. However, DPOAEs should be used as a screening tool only, as conventional pure-tone audiometry remains the more comprehensive measure of hearing sensitivity.