Otoacoustic emissions: a new method for newborn hearing screening

Abstract

Pediatric deafness is a handicap affecting approximately 2/1000 newborns. Currently, its diagnosis is markedly delayed, since it occurs approximately at 24 to 36 months of age; at this age rehabilitation procedures (i.e., acoustic prosthesis, speech therapy, psychological interventions on the family, or cochlear implants in the most serious situations) are unable to ensure a complete development of both the voice and the speech, thus preventing the full participation of the deaf child in social living. The turning point has taken place when methods and techniques were developed; they are aimed at the very early diagnosis of infantile deafness and are based on the recordings of otoacoustic emissions, that is, acoustic signals of extremely weak intensity originating in the inner ear, which not only is a passive transducer, but is able to generate sounds also. Any lack of or any change in otoacoustic emissions is a accurate index of disabling deafness. The test under study allows to perform selectively a mass screening on newborns (it is carried out 2 or 3 days after birth) since it is definetely non-invasive, it is done very rapidly (a few seconds only), it is cost-effective and higly reliable. The newborn hearing screening is being accepted, at a faster growing pace, by an increasing number of health systems in the whole world.