Transient Evoked Otoacoustic Emissions Test Research Articles

Hearing threshold assessment post grommet insertion. Is it reliable?

We aimed to investigate whether auditory brainstem response (ABR), assessed immediately after grommet insertion, was an accurate measure of hearing threshold. Ten children were recruited (20 ears). Patients underwent transient evoked otoacoustic emission (TEOAE) and ABR tests before and after grommet insertion under general anaesthetic. A third assessment was conducted at a six-week review, without anaesthetic or sedation. The hearing threshold in dB and the presence of TEOAE were recorded by senior audiologists. The results of each investigation were compared. At review, only 15 ABR and 17 TEOAE tests, of a possible 20, were recorded. Transient evoked otoacoustic emissions were recorded in 30 per cent of ears pre-operatively, 20 per cent of ears post-operatively and 82 per cent of ears at six-week review. The average ABR thresholds were 23.75 dB (range 10-45 dB) pre-operatively, 27.25 (range 15-40 dB) post-operatively and 15 dB (range 5-25 dB) at six-week review. Comparing pre- and post-operative assessment, decreased thresholds were seen in six ears and elevated thresholds in 11. Comparing the six-week review ABR with the post-operative ABR, 13 ears had decreased thresholds, by as much as 20 dB. Thresholds of 35 dB or greater were measured in six ears immediately after grommet insertion (maximum 40 dB). Threshold shifts of 15 dB or greater was observed in seven ears. The intra-subject variation was shown to be significant (p<0.001) when repeated measures analysis of variance was applied. We conclude that there is evidence that ABR can be inaccurate after grommet insertion, overestimating hearing thresholds. We believe that the mechanism by which the error is realised is temporary threshold shift.

An alternative strategy for universal infant hearing screening in tertiary hospitals with a high delivery rate, within a developing country, using transient evoked oto-acoustic emissions and brainstem evoked response audiometry

To formulate an alternative strategy for universal infants hearing screening in an Indian tertiary referral hospital with a high delivery rate, which could be extended to similar situations in other developing countries. The system should be able to diagnose, in a timely fashion, all infants with severe and profound hearing losses. One thousand newborn were randomly selected. All underwent testing with transient evoked oto-acoustic emissions (TEOAE) in the first 48 hours of life. All TEOAE failures were followed up and repeat tests were performed at three weeks, three months and six months of age. Infants with acceptable TEOAE results at any of the four ages were discharged from the study. Infants with unacceptable TEOAE results at all the four ages underwent brainstem evoked response audiometry and oto-endoscopy. The 'pass rate' for TEOAE testing was calculated for all four ages. The time taken to perform TEOAE and brainstem evoked response audiometry was recorded for all subjects. These recordings were statistically analysed to find the most suitable strategy for universal hearing screening in our hospital. The pass rate for TEOAE was 79.0 per cent at < or =48 hours, 85.0 per cent at three weeks, 97.0 per cent at three months and 98.0 per cent at six months. The average time taken to perform the test was 12 minutes for TEOAE and 27 minutes for brainstem evoked response audiometry. Obstructed and collapsed external auditory canals were the two factors that significantly affected the specificity of TEOAE in infants < or =48 hours old. The concept of screening all neonates within the first 48 hours of life is impractical because the specificity of TEOAE is lowest at that age. Many false positive results are generated, such that a larger number must undergo brainstem evoked response audiometry, wasting time and resources. This can easily be avoided by delaying TEOAE screening until three months of age, when it has a substantially lower false positive outcome. We expect that implementation of this alternative strategy in our hospital will maximise the benefits of such a programme.

Cochleovestibular Dysfunction in Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a rheumatic disease characterized by chronic inflammation. The aim of this study was to evaluate the functions of the cochlea and the vestibular system in patients with AS. The study group consisted of 32 patients with AS and 30 healthy volunteers as a control group. Otorhinolaryngologic examinations were performed in all patients together with pure-tone audiometry, speech tests, impedancemetry, transient evoked otoacoustic emission (TEOAE) and electronystagmography (ENG). A significant difference was found between the 2 groups with regard to pure-tone averages at high frequencies in each ear (p < 0.05). The rates of reproducibility in TEOAE testing were significantly lower in patients with AS (p = 0.03). The signal-to-noise rates of the response values were lower at all frequencies in patients with AS, but a statistically significant difference was only observed at 2, 3 and 4 Hz (p < 0.05). ENG revealed pathologies in 11 patients with AS (34%), 8 of which were central (25%) and 3 of which were peripheral (9%). No correlation was found between cochleovestibular dysfunction and age, sex, disease duration, activity and medication taken. This study demonstrated that there is an association between AS and cochleovestibular dysfunction.

Influence of anaesthetic agents on transient evoked otoacoustic emissions and stapedius reflex thresholds

This aim of this study was to determine the effect of anaesthetic agents on stapedius reflex (SR) thresholds and transient evoked otoacoustic emissions (TEOAE). Fifty patients who were scheduled for operation and who had normal hearing were included in the study. All were given midazolam for premedication and propofol for induction. Anaesthesia was maintained in five different ways in each group of 10 patients. Groups I-IV received inhalational anaesthesia: group I received 70 per cent N2O plus 30 per cent O2, group II sevoflurane, group III desflurane and group IV halothane. Group V received total intravenous anaesthesia with propofol plus sufentanil. The SR and TEOAE of the patients were measured four times: on the day before surgery (first measurement), after premedication (second measurement), after induction of anaesthesia (third measurement) and during maintenance of anaesthesia (fourth measurement). Midazolam significantly increased ipsilateral and contralateral SR thresholds and decreased TEOAE wave reproducibility. Propofol significantly increased only the SR thresholds. The other anaesthetic agents significantly increased only the contralateral reflex thresholds. Of these, the highest increase was seen after sevoflurane and the lowest after halothane. The changes in TEOAE wave reproducibility due to anaesthetic agents used for maintenance were not significant. We concluded that midazolam premedication may affect audiological evaluation with SR and TEOAE tests, and sevoflurane should not be used when it is necessary to measure SR under general anaesthesia.

Intratympanic dexamethasone injection effects on transient-evoked otoacoustic emission

Purpose To investigate the effects of intratympanic dexamethasone injection, which is done because of tinnitus, on transient evoked otoacoustic emission (TEOAE) and so determine whether given dexamethasone cause any damage in the inner ear. Patients and methods Twenty-six patients, aged between 32 and 75, with subjective tinnitus, were randomly selected. The selected patients were the ones whose improvement had not been achieved through minimum 6 months' medical therapy (eg, Ginkgo biloba extract EGb 761, betahistidine, and trimetazidin) and who were free of systemic or otolaryngologic disease (hypertension, diabetes mellitus, hypo/hypertyroidi, hypercholesterolemia, Ménière disease, and otosclerosis). Before and after the injections, audiometry including high-frequency tinnitus matching and TEOAE tests were done. The injections of 4 mg/mL dexamethasone were done 5 times in fixed protocols on days 0, 2, 4, 6, and 8. After each injection, the patients were kept supine for 60 minutes with the head turned 45° to opposite ear. Paired t test was used to compare the beginning and final measurements. Results Temporary pain and vertigo attacks which lasted at most for 15 minutes occurred in some patients only during injections. Neither infection nor persistent perforation occurred in any patients. After the management, there was no significant difference on patient's pure tone averages ( P = .067) and high-frequency averages ( P = .592). When the obtained TEOAE results before and after management were compared, the only significant increase was detected in the reproducibility values ( P = .042). There was no significant difference in other TEOAE parameters which are stimulus stability, stimulus intensity, and overall signal-to-noise ratio ( P > .05). There is no fixed criteria for rejecting a response solely on the reproducibility. However, a high value of the reproducibility (or increase in reproducibility) is always meaningful. Conclusion Intratympanic dexamethasone used for management in many indications, primarily in Ménière and tinnitus patients, was found to increase the reproducibility values of otoacoustic emission. Despite the fact that there was not a reasonable increase in the responses coming from the outer hair cells, the result was considered positive for the study as the responses did not decrease. It is found out that 4 mg/mL dexamethasone given intratympanically does not adversely affect the outer hair cell function as measured by otoacoustic emission. Within the limits of this study, dexamethasone appears to be safe when given intratympanically.

Tympanometry and TEOAE Testing of Children with Down Syndrome in Special Schools

Despite widespread awareness that children with Down syndrome are particularly susceptible to hearing pathologies, the audiological status of students with Down syndrome in special schools is all too often unknown. Unfortunately, hearing screening for this population is unable to rely on standard, behavioural test batteries. To facilitate future improvements in screening protocols, this study investigated the results of tympanometry and transient evoked otoacoustic emission (TEOAE) testing for a group of children with Down syndrome. Assessments were not conducted in the artificial context of a clinic or laboratory, but within the school environment. Outcomes are reported for 27 subjects with a mean age of 10 years 5 months (SD = 4;11). Tympanometry testing was failed in at least one ear by 41.7% of subjects, while a failure rate of 81.5% of subjects was observed for TEOAE testing. Therefore, it is concluded that immediate review of hearing screening programs for students with Down syndrome is highly advisable.

Methodological factors involved in neonatal screening using transient-evoked otoacoustic emissions and automated auditory brainstem response testing

The methodological factors involved in screening neonates for hearing loss, using transient-evoked otoacoustic emissions (TEOAEs) and automated auditory brainstem responses, have been evaluated from a large sample of neonates. The risk factors, commonly used to select babies for a targeted screen, have very little correlation with failing TEOAE testing. The parameters used to determine passing or failing the TEOAE test and the false alarm rate change markedly with age in the first few days of life as, of course, did the percentage of babies who failed the test. The stimulus level used was the default setting for the Otodynamics equipment but the stimulus level measured in the ear canal decreased over the first 140 h of life. It is thought that this reflects the impedance changes in outer and middle ears and possible changes in middle ear dynamics. The methodological variables investigated here can illuminate some of the differences in previous reports of neonatal screening, in particular the reported hit and false alarm rates.

Hearing screening for children in community settings using transient evoked otoacoustic emissions

Abstract Despite widespread investigation and utilization of transient evoked otoacoustic emission (TEOAE) hearing screening programmes in the neonatal population, limited research has occurred into the applicability and particulars of TEOAE testing of other paediatric ages. Further consideration must be afforded to screening beyond the neonatal stage. Later, community-based options for hearing screening include the infant period and/or upon entry to primary school, or special education settings. The present researchers have conducted TEOAE screening and analyses for 627 subjects in the two-month-old age group, 940 children of school-entry age and 489 subjects studying in special schools. In particular, TEOAE normative data were provided for specific groups and environments, and non-pathological effects on the results were described. The technical findings of this paper lend themselves to a vast array of immediate clinical applications to improve hearing screening of two-month-old infants, six-year-old sc...

Transient evoked otoacoustic emissions in children studying in special schools

Objectives: The present study aimed to investigate the feasibility and practicalities of testing children in special school settings using transient evoked otoacoustic emissions (TEOAE) and tympanometry. Children studying in special schools, particularly those with intellectual impairment, may be highly susceptible to hearing pathologies and can be difficult to assess using traditional test batteries. Researchers have recently suggested the possible applicability of TEOAE testing, in lieu of conventional behavioral methods, as a hearing screening device for persons with intellectual impairment. However, to date, few publications have detailed the particulars and results of such testing. Methods: A total of 489 children, with a mean age of 9.6 years, were tested in 15 special schools. Case information was obtained regarding birth history, medical history and type/degree of impairment, for later comparison with screening results. TEOAEs were collected using Quickscreen mode of the ILO292 Otodynamics Analyzer, whilst tympanometry was performed utilizing a Madsen Zodiac 901 Middle Ear Analyzer. Results: In total, 80% of students were able to be tested using TEOAEs. Average test time per ear was 2 min. However, a large proportion (40% of those able to be tested) failed TEOAE testing in at least one ear. No significant effects were found between could-not-test (CNT) cases and case history factors. A significant difference in TEOAE failure rates was found across history of neonatal special care nursery residency and history of parental concern regarding possible hearing impairment. Failure rates were higher for those who indicated positive histories. A total of 74% of subjects could be tested using tympanometry, with 25% of those able to be tested failing in at least one ear. Notably, neither type nor degree of impairment had any significant bearing on CNT or failure rates for tympanometry or TEOAE screening. Conclusions: Findings of the present investigation lend support to the review of hearing screening programs for children in special schools, with TEOAEs presenting as a potential alternative procedure. Further examination of the performance measures of protocols incorporating TEOAEs would now be advantageous.

Relationships between otoacoustic emissions and auditory brainstem responses in neonates and young children: a correlation and factor analytical study.

To establish relationships among transient evoked otoacoustic emission (TEOAE) and auditory brainstem response (ABR) variables in a sample of normal hearing neonates and young children, ranging in age from approximately 3 weeks to 4 years. Retrospective, non-randomized, cross-sectional analysis of clinical data obtained at a tertiary care medical center. Pearson product moment and Spearman rank order correlation analyses to evaluate pairwise relationships between TEOAE variables, ABR variables and age; factor analysis, to identify the structural composition and dimensionality of these relationships. Significant pairwise correlations were obtained between variables within each test paradigm (TEOAEs, ABRs) and between ABR absolute and interpeak latencies with age. However, the most striking effect was the absence of strong correlations between ABR and TEOAE variables, indicating that these test measures provide independent information about auditory system integrity and sensitivity. Two factors, accounting for over 55% of the variance, characterized this data set: 1) a frequency-dependent OAE factor, which showed an inverse relation between biologic noise and whole wave percent reproducibility and half-octave band TEOAE amplitudes; and 2) a central nervous system (CNS) maturational factor, which showed an inverse relationship between age and certain absolute and interpeak ABR latency components. TEOAE and ABR test results provide unique and functionally independent information about normal auditory system integrity and sensitivity. Therefore, a combination of both tests is well suited for use within a pediatric test battery. These results confirm that biologic noise and age at test differentially affect OAE and ABR test measures, and both effects require consideration during data acquisition and interpretation.

New York State universal newborn hearing screening demonstration project: effects of screening protocol on inpatient outcome measures.

To examine differences among various test protocols on the fail rate at hospital discharge for infants in the well-baby nursery (WBN) and neonatal intensive care unit (NICU) who received hearing screening through a universal newborn hearing screening demonstration project. The outcomes of several screening protocols were examined. Two technologies were used: transient evoked otoacoustic emissions (TEOAEs) alone or in combination with the auditory brain stem response (ABR). The performance of test protocols in both nurseries within eight hospitals was examined over a 2- to 3-yr period. In the WBN, six hospitals used a screening protocol of TEOAE technology first followed by an ABR (automated or conventional) technology screening for newborns who referred on TEOAE screening. Two hospitals used TEOAE only in the WBN. Seven hospitals used screening protocols in the NICU that used a combination of TEOAE and ABR technologies (TEOAE technology administered first or second, before or after TEOAE, or TEOAE and ABR tests on all infants). Only one hospital used TEOAE technology exclusively for hearing screening. Significant differences among screening protocols were found across hospitals in the first, second, and third years of the program. The combination of TEOAE technology and ABR technology (a two-technology screening protocol) resulted in a significantly lower fail rate at hospital discharge than the use of a single-technology (TEOAE). Fail rates at discharge were twice as high using the one-technology protocol versus two-technology protocol, even when the best outcomes from program year 3 were considered exclusively. Results of two-technology versus one-technology protocols were similar in the NICU. Use of a second technology for screening TEOAE fails significantly reduced every hospital that used the protocol's fail rate at discharge. A two-technology screening protocol resulted in significantly lower fail rates at hospital discharge in both the WBN and NICU nurseries than use of a single-technology (TEOAE) hearing screening protocol.

Confirmation of deafness in infancy

AIMTo assess delay in confirming hearing impairment in infants identified by universal neonatal screening and to investigate the causes.PATIENTSInfants identified from 25 199 babies screened from January 1992 to December...

Neonatal otoacoustic emission screening and the identification of deafness.

Using transient evoked otoacoustic emissions (TEOAEs), a two stage screen with the testing of failures by auditory brainstem response (ABR), has been implemented in Whipps Cross Hospital in East London. From January 1992 to 1995, 11,606 infants received an initial TEOAE test. Once initial difficulties were resolved, coverage of district residents remained stable at 91.5%. Long term follow up of the cohort is being undertaken. Of those receiving an initial test, 13% failed in both ears. Only 1.75% of the cohort failed both stages of the TEOAE screen bilaterally. These infants were tested by ABR. The yield of infants with a bilateral permanent hearing loss of moderate or worse degree was 2/1000. The overall cost of implementing the programme was not prohibitive and the cost per hearing impaired child detected was little more than the widely accepted notional cost of identifying such children through targeted at risk screens. The screen was clearly sensitive. The priority for such universal TEOAE programmes, however, is to increase specificity without losing this sensitivity.

The effects of noise in transient EOAE newborn hearing screening

The use of transient evoked otoacoustic emissions (TEOAEs) has been advocated as the first stage entry level technique for universal newborn hearing screening. To date, the majority of TEOAE infant testing has been conducted under controlled noise conditions; i.e., acoustically treated sound suites. As a result, previously reported TEOAE evaluations may not realistically represent test outcomes in actual hospital screening settings. The purpose of this study was to compare the results of TEOAEs with auditory brainstem response (ABR) hearing screening in a hospital environment where noise conditions do not meet the same ambient noise specifications as those found in sound rooms. A total of 119 stable newborns (67 high risk, 52 normal) ranging in post-conceptual age (PCA) from 33 to 41 weeks received both the ABR and TEOAE screening protocols. Testing was conducted at crib side in either the well baby nursery or the neonatal special care unit (NSCU). Newborn ABR screening failed 8 (3.8%) of 224 ears, whereas TEOAE testing failed 85 (38.4%) and could not test another 22 (9.8%) ears. That is, only 117 (52.2%) of the 224 ears passed the TEOAE test. Using the ABR as the reference test the specificity and sensitivity for TEOAE was 52% and 50%, respectively. Noise levels measured by the probe microphone within the ear canal exceeded those levels (30 dBA SPL) recommended for TEOAE newborn hearing screening. Results of this study suggest that under realistic hearing screening test conditions, TEOAE results may be influenced by the level of noise in the testing environment. Whereas significant advances have been attained in TEOAE measurement during the past decade, clinical evidence supports the need for continued research aimed at solving problems before this technique can be used efficiently for newborn screening.