Transient evoked otoacoustic emissions (TEOAEs) in new-borns: normative data

Main outcomes from the first two years of France's screening programme for neonatal permanent hearing loss through a descriptive study

AIM

This study aimed to evaluate the implementation of France's neonatal hearing loss screening programme two years after its launch, and to estimate permanent bilateral neonatal hearing loss (PBNHL) prevalence and distribution by severity.

METHODS

This descriptive study used aggregated regional data on all births in France in 2015-2016. Screening coverage, refusal rate, positive predictive value (PPV), proportion of children with suspected PBNHL, PBNHL prevalence and distribution by severity were calculated.

RESULTS

800,000 neonates were eligible for the screening programme per year. Between 2015 and 2016, screening coverage increased (83.3 vs 93.8%; p<0.001), and the refusal rate remained stable (0.1%). In 2016, when considering the additional tests performed several weeks after birth, the proportion of suspected PBNHL neonates decreased (1.4 vs 0.9%) while the PPV increased (4.7 vs 7.6%). In 2015, the estimated prevalence of PBNHL (moderate to profound) was 0.09% (95% CI 0.08-0.10). Among neonates with >=41 decibels deficit, 56.8%, 16.6%, and 26.6% had moderate, severe and profound hearing loss, respectively.

CONCLUSION

The national target of 90% screening coverage was exceeded. The additional test could be useful to avoid overcrowding in diagnostic structures. Diagnostic data quality must be improved to confirm PBNHL prevalence and distribution by severity.

Our newborn hearing screening results

OBJECTIVE:

The aim of the study was to evaluate the results of neonatal hearing screening in our hospital with the help of literature and to question and reveal the risk factors to gain healthy individuals and to raise awareness for all health workers and the public who are interested in this subject.

METHODS:

A total of 16,388 newborn infants were evaluated between October 2009 and January 2018. All newborns were screened with transient evoked otoacoustic emissions (TEOAEs) test. Risk factors were investigated. The test repetition and auditory brainstem response (ABR) measurements were performed on newborns who could not pass the TEOAE test and the newborns in the risky group after 15 days.

RESULTS:

A total of 116 newborns (0.7%) were suspected to have hearing loss. Twenty-seven newborns (0.16%) were found to be in intensive care unit. Twelve newborns (0.07%) had permanent hearing loss. Then, in order: 9 newborns (0.05%) had received phototherapy and 7 newborns (0.04%) were born to consanguineous marriages. In addition, 3 newborns (0.02%) had a low birth weight and 1 newborn (0.006%) had a history of fever.

CONCLUSION:

Screening tests should be performed in all newborns for early detection of hearing loss. Even though frequency of hearing loss is higher in newborns with risk factors, the treatment should be started within 6 months, the latest, and newborns should be referred for rehabilitation and training.

Effect of age on click-evoked otoacoustic emission: A systematic review

OBJECTIVE:

The aims of this study were to investigate the changes of the total intensity of transient evoked otoacoustic emission (TEOAE) and signal-to-noise ratio in various frequency bands as a function of aging, and to explore the role of age-related decline of cochlear outer hair cells.

DATA SOURCES:

The literature was searched using the PubMed database using ‘transient-evoked otoacoustic emissions’ as a keyword. Articles were limited as follows: Species was ‘Humans’; languages were ‘English and Chinese’; publication date between 1990-01-01 and 2010-12-31. The references of the found were also searched to obtain additional articles.

DATA SELECTION:

Inclusion criteria: (1) Articles should involve the total TEOAE level or signal-to-noise ratio. (2) The measurement and analysis system used was Otodynamics ILO analysis system (ILO88, ILO92, ILO96 or ILO292). (3) Studies involved groups of greater than 10 subjects and TEOAE results were from normally hearing ears. (4) If more papers from the same author or laboratory analyzed the same subjects, only one was used.

MAIN OUTCOME MEASURES:

The correlations of the age scale with the total level and signal-to-noise ratio of TEOAE was determined, respectively.

RESULTS:

(1) TEOAE total level gradually increased until 2 months of age, and then decreased with increasing age. Significant negative correlations between total TEOAE level and age were found (r = –0.885, P = 0.000). (2) The most rapid decrease of TEOAE amplitude occurred at 1 year old. The total TEOAE level decreased about 4.25 dB SPL between 2 months to 1 year old, then about 0.26–0.52 dB SPL from 1 year to 10 years old, about 0.23 dB SPL from 11 years to 25 years old, and about 0.14 dB SPL from 26 years to 60 years old. (3) The signal-to-noise ratio in the frequency bands centered at 1.5, 2, 3 and 4 kHz decreased with increasing age after 2 months of age. Significant negative correlations between the signal-to-noise ratio and age were found for frequency bands ranging from 1.5 kHz to 4 kHz, with the highest correlations at 4 kHz (r = –0.890, P < 0.01), then at 3 kHz (r = –0.889, P < 0.01), at 2 kHz (r = –0.850, P < 0.01) and at 1.5 kHz (r = –0.705, P < 0.05). Conversely, a positive correlation between the signal-to-noise ratio centered at 1 kHz and age was found, but was not statistically significant (r = 0.298, P = 0.374).

CONCLUSION:

The total TEOAE response level decreased with increasing age after the first 2 months of age. The signal-to-noise ratio also decreased with increasing age in frequency bands above 1.5 kHz. The signal-to-noise ratio in higher frequencies decreased faster than in lower frequencies, leading to the maximum signal-to-noise ratio shift form 3.2–4.0 kHz in neonates to 1.5 kHz in adults, and further decreasing the total TEOAE response level. The age-related TEOAE spectrum peak shift is most likely because the outer hair cells functioning in higher frequencies are more prone to damage than those for lower frequencies.

Post-processing analysis of transient-evoked otoacoustic emissions to detect 4 kHz-notch hearing impairment--a pilot study

Background

To identify a parameter to distinguish normal hearing from hearing impairment in the early stages. The parameter was obtained from transient-evoked otoacoustic emissions (TEOAEs), overcoming the limitations of the usually adopted waveform descriptive parameters which may fail in standard clinical screenings.

Material/Methods

Audiometric examinations and TEOAE analysis were conducted on 15 normal ears and on 14 hearing-impaired ears that exhibited an audiometric notch around 4 kHz. TEOAE signals were analyzed through a multivariate technique to filter out the individual variability and to highlight the dynamic structure of the signals. The new parameter (named radius 2-dimension – RAD2D) was defined and evaluated for simulated TEOAE signals modeling a different amount of hearing impairment.

Results

Audiometric examinations indicated 14 ears as impaired-hearing (IH), while the TEOAE ILO92 whole reproducibility parameter (WWR) indicated as IH 7 signals out of 14 (50%). The proposed new parameter indicated as IH 9 signals out of 14 (64%), reducing the number of false negative cases of WWR.

Conclusions

In this preliminary study there is evidence that the new parameter RAD2D defines the topology and the quantification of the damage in the inner ear. The proposed protocol can be useful in hearing screenings to identify hearing impairments much earlier than conventional pure tone audiometry and TEOAE pass/fail test.

Ligurian experience on neonatal hearing screening: clinical and epidemiological aspects

AIM

Early identification and rehabilitation of newborns with congenital hearing impairment (HI) by Universal Neonatal Hearing Screening (UNHS).

METHODS

The neonatal population was divided into two groups: babies with No Audiological Risk (NAR), and babies With Audiological Risk (WAR). NAR neonates underwent OAE testing, and in case of a doubtful (Refer) result, ABR testing was carried out. All WAR newborns underwent ABR testing within the third month of life.

RESULTS

Between February 1, 2002 and December 31, 2004, UNHS was carried out on 32 502 newborns at the 13 regional birth centres, representing 98.7% of the whole regional neonatal population. The prevalence of HI in the population we tested was estimated at about 1 per thousand, while Bilateral Hearing Impairment (BHI) was estimated at 0.65 per thousand. A 3.7% prevalence of HI and a 2.8% prevalence of BHI was observed among the WAR population. Median age at the end of the diagnostic procedures was 6.7 months in the WAR population and 6.9 months in the NAR population.

CONCLUSIONS

Our project is based on two levels of testing, which resulted in a 0.28% false-positive rate with 100% sensitivity and 99% specificity. Our screening is the first Italian experience that has been extended to a whole region and the results prove that regional neonatal hearing screening is feasible.

Neonatal hearing screening: evaluation of tone-burst and click-evoked otoacoustic emission test criteria

OBJECTIVE

Click-evoked otoacoustic emissions (CEOAEs) are widely used in universal neonatal hearing screening programs. A common finding in many such programs is a relatively high false-positive rate. This is often due to infant physiological noise adversely affecting the emission recording, leading to a "refer" screening outcome. In an attempt to reduce false-positive screening outcomes related to the effects of noise on otoacoustic emission response detection, tone-burst-evoked otoacoustic emissions (TBOAEs) were included in a neonatal hearing screening program because TBOAEs may elicit a greater signal-to-noise ratio than CEOAEs. The research project compared the pass/refer rate for a CEOAE-based test using established pass/refer criteria with the pass/refer rate for screening criteria that were based on TBOAE results alone or on combined CEOAE and TEOAE results.

DESIGN

Neonates were recruited at the Hong Kong Adventist Hospital, and both CEOAEs and TBOAEs were performed. Six passing criteria were used in this study, based on CEOAEs only; CEOAEs plus 1 kHz TBOAEs; CEOAEs plus 2 kHz TBOAEs; CEOAEs plus 3 kHz TBOAEs; CEOAEs plus 1, 2, and 3 kHz TBOAEs; and TBOAEs only.

RESULTS

Data from 298 neonates (546 ears) were obtained. Criteria set 1, using CEOAEs only, demonstrated a pass rate of 79.1%, and 114 ears were referred. Criteria set 2, using CEOAEs together with TBOAEs recorded at 1 kHz, passed 39 more ears than Protocol 1, and the pass rate was 86.3%. Hence, the overall referral rate for total number of screened ears decreased by 7.2 percentage points. Criteria set 3, using CEOAEs together with TBOAEs recorded at 2 kHz, and Criteria set 4, using CEOAEs in conjunction with TBOAEs recorded at 3 kHz, gave pass rates similar to Criteria set 1. Criteria set 5, using TBOAE information at frequencies where CEOAEs were not rated as "pass," raised the pass rate from 79.1 to 87.6%, reducing the overall referral rate by 8.5 percentage points. Criteria set 6, in which neonates were screened with TBOAEs recorded at 1, 2, and 3 kHz, gave a pass rate of 78.4%, similar to results for the CEOAE-only procedure.

CONCLUSIONS

Both Criteria sets 2 and 5, which combined CEOAE and TBOAE recordings, gave significantly higher pass rates than Criteria sets 1, 3, 4, and 6. The results suggest that the introduction of combined CEOAE and TBOAE protocols may assist in the reduction of refer outcomes, and hence the false-positive rates, of neonatal hearing screening programs.

The effect of the number of averaged responses on the measurement of transiently evoked otoacoustic emissions in newborns

OBJECTIVE

The aim of this study was to examine the effect of the number of averaged responses on the measurement of transiently evoked otoacoustic emissions (TEOAEs).

METHODS

The study was performed on the background of a universal newborn hearing screening program implemented in Iaso Maternity Hospital. Two groups of full-term newborns with normal otoacoustic emissions were studied. The first group included 58 newborns (115) ears, in which 260 low-noise samples, provided by the default setting of the equipment used (ILO88), were presented. The second group included 58 newborns (113) ears, in which 20-50 averaged responses were presented, until the "pass" criteria would be met. Statistical comparison between the following parameters recorded during TEOAE measurement was performed: Overall response, signal-to-noise ratios, reproducibility (whole and partial), stimulus intensity, stimulus stability, input noise, noise rejection level and duration of testing.

RESULTS

Statistically significant differences were found in most of these parameters, except for overall response, stimulus intensity and noise rejection level.

CONCLUSIONS

Although a smaller number of clicks is usually sufficient to obtain a "pass" in newborn hearing screening programs, the quality of recording of TEOAEs is significantly improved by increasing the number of averaged low-noise responses.

Despistaje de la hipoacusia neonatal: resultados después de 3 años de iniciar nuestro programa

Since the 90s there increasing interest in early detection of neonatal hearing loss due to the feasibility of universal neonatal screening as well as to the possibility of early intervention. This has led to set up neonatal screening programs based upon otoacoustic emissions and to a great increase in the number of publications in the field. Our hospital started a neonatal hearing loss screening program using otoacoustic emission in March 2000. We used a Capella Cochlear Emissions (MADSEN electronics) equipment. Until May 2003 we have performed the test in 6372 children with a median age of 71 days. In our study, the sensibility of the test was 90.9% and the specificity 99.7%. Our results are similar to those reported in the literature although the age of the children was higher and we have found an incidence of hearing loss lower than other studies.

A Two-stage bipodal screening model for universal neonatal hearing screening

OBJECTIVE

A model is proposed for universal neonatal hearing screening.

METHODS

The screening model is two-staged because it consists of a first test and, in case of failure (1.4% of the subjects), of a retest 3 weeks later. It is bipodal because it involves both the hospital audiologic department and a central Well Baby Organization. The idea is to have a maximal number of newborns tested at the maternity by trained audiologists and to have the Well Baby Organization trace and chase the missing subjects. The model has been evaluated during 1 calendar year (1999) in a maternity with 2,012 newborns.

RESULT

The result is a coverage of 99.3%. Most newborns (97.3%) were tested at the maternity ward with a total time investment of less than 15 minutes per child. The actual test time is 2 minutes, 12 seconds (median value). The Well Baby Organization keeps track of all the results and has to test no more than 2% of the newborns. Sensitivity and specificity were not the primary outcomes of this evaluation, but they were similar to those of a previous study evaluating the screen procedure on a larger scale, giving a sensitivity of approximately 100% and a false alarm rate of 1/1,000.

CONCLUSION

These figures demonstrate that universal neonatal hearing screening is feasible within the existing health care structure, with unprecedented coverage, sensitivity, and specificity.