Otoacoustic Emissions

Hair cell health check, foundation of newborn screening

Overview

Healthy outer hair cells amplify incoming sound and emit faint echoes back, OAEs, recordable with a soft probe microphone. Present emissions mean the cochlea up to the outer hair cells works. They vanish with even mild hearing loss, noise exposure, or fluid. Because they need no behavioral response, they are the backbone of newborn hearing screening, done in seconds during sleep. Absent OAEs trigger ABR follow up. They also monitor cochlear health during ototoxic chemotherapy.