The role of current audiological tests in the early diagnosis of hearing impairment in infant.

This study aims to compare the various audiological tests that are currently available as screening tools for infant hearing assessment. In developing countries, which have limited resources, it is imperative to design a screening programme that is easy to perform, gives accurate results, has good patient acceptability and is cost effective. Fifty infants, 3-12 months of age, were subjected to BOT for hearing, transient-evoked oto-acoustic emissions (TEOAEs), automated auditory brainstem response (AABR) test, auditory brainstem evoked response (ABR) testing and auditory steady state response (ASSR). The sensitivity and specificity of the various tests was calculated, with ABR test as the gold standard. We also compared them for average time taken, cost factors, ease of performance, number of repeat tests required and patient acceptability. All the screening tests, TEOAE, AABR and behavioral observation test had reasonably high sensitivity. Specificity was highest for behavioral observation testing (67.7 %) and AABR (64.5 %), but low for OAE test (48.3 %). The cost and time taken for each test was least for the behavioral observation test, which also did not require any repeat testing. TEOAE and AABR incur a recurring cost of approximately one dollar per test. However, in 12 and 28 % of the babies had to be called back for repeat testing, respectively. ASSR, as a diagnostic test, has a 100 % sensitivity and high specificity but scores down on the cost involved, time taken and the number of repeat tests required. Overall parent acceptability was the highest for behavioral observation test, as it was non-invasive and easy to perform. Behavioral observation combined with TEOAE/AABR, can be fairly accurate as screening tests for hearing loss in infants. Considering its ease of performance and low cost, behavioral observation could be used as a screening test for detection of hearing loss in infants, in those countries/places where universal neonatal hearing screening is not yet available.