Role of Otoacoustic Emissions in Hearing Assessment of Neonates: A Prospective Observational Study

Hearing plays an important role for children in learning speech and language, socialization and cognitive development. The child learns to speak based on what is heard (Rundjan et al. in Sari Pediatr 6(4):149-154, 2005). The aim of the study was to find out the percentage of hearing loss by OAE among low risk and high risk neonates. All the neonates (Low and High risk) born in a tertiary care center were screened by OAE before their discharge from the hospital and after stabilizing high risk neonates. The referred neonates were followed after two weeks. Total 722 neonates were screened of which 130 were high risk and 592 were low risk. Neonates with Serum bilirubin > 20 mg/dl or requiring exchange transfusion were excluded as OAE will be unreliable in them and they should be subjected to BERA directly. Percentage of bilateral hearing loss came to be 4.2%, 4 participants were lost to follow up and percentage of hearing loss on subsequent OAE came to be 11.6%. Low birth weight was an important risk factor for hearing loss (p value significant on initial and follow-up). Percentage of hearing loss with low birth weight, hyperbilirubenemia, low apgar score and prematurity to be 16%. Mechanical ventilation contributed 13% of total hearing loss followed by ototoxicity. Neonates with family history of childhood SNHL, in utero infection, craniofacial anomaly and bacterial meningitis contributed 3% of total hearing loss. On subsequent follow-up, one neonate was low-risk and the other 25 were high risk, of which 3 high risks showed sustained OAE refer. However the low risk neonate had normal outer hair cell function i.e. OAE pass. This study clearly demonstrates importance of Universal Neonatal Hearing Screening Programme so that hearing loss can be detected as early as possible and possible intervention can be taken at the earliest.