Comparative Evaluation of Transient Evoked Oto-Acoustic Emissions and Brainstem Evoked Response Audiometry as Screening Modality for Hearing Impairment in Neonates

Abstract

Objective This study was designed to evaluate Transient Evoked Oto-acoustic Emission (TEOAE) as screening modality for hearing impairment in neonates. Brainstem Evoked Response Auditometry (BERA) was used as gold standard diagnostic tool in this study. The factors affecting the specificity of TEOAE were also studied. Methods The study group of 200 randomly selected neonates was subjected to TEOAE and BERA (400 ears). Oto-endoscopy was done in all TEOAE failures and a repeat test was done after suction cleaning of blocked external auditory canal (EAC). Results Otoscopic evaluation of all 52 TEOAE failures was done. EAC obstruction was noticed in 31 ears and 4 ears showed collapsible EAC. TEOAE was repeated after suction cleaning of the obstructed EAC and using long probe tips for collapsible EAC. This improved the Pass rate of TEOAE from 87% to 92%. EAC obstruction and collapsible EAC were the two factors identified in this study that significantly affected the specificity of TEOAE as a screening test. Pass rate of TEOAE in <48 hrs age group was found to be 55.5%, which was nearly half of over-all pass rate. This was because of high prevalence of obstructed EAC in this age group. TEOAE was found to be a rapid screening tool as average time taken for BERA was 35 min/neonate and for TEOAE was 17.4 min/neonate. Acceptability of TEOAE was found to be higher as compared to BERA. Conclusions TEOAE is a simple and rapid test with relatively higher acceptability. But, the low sensitivity and specificity are the main shortcomings that take away from TEOAE, the status of independent screening modality for hearing impairment in neonates. TEOAE cannot completely replace BERA as screening modality for hearing impairment in neonates, however can complement it.