OTOACOUSTIC EMISSIONS IN FULL-TERM NEWBORNS AT RISK FOR HEARING-LOSS

Distortion product otoacoustic emissions (DPOEs) and click-evoked otoa coustic emissions (CEOEs) characteristics of the normal newborn popula tion have been previously reported in the literature. There is little information about DPOE evaluations in the newborn population at risk f or hearing loss. The authors now report the DPOE and/or CEOE data from six full-term subjects at risk for hearing loss or with highly suspec ted hearing loss. These subjects were less than 1 year of age and at r isk for hearing loss secondary to a history of hereditary hearing loss , meningitis, hyperbilirubinemia, and ototoxic drug exposure. Audiomet ric evaluation included auditory brainstem responses (ABR), behavioral observation audiometry, and tympanometry. The CEOEs and DPOEs were fo und to be decreased or absent in the subjects with suspected hearing l oss secondary to cochlear pathology; they were found to be normal in a subject with a suspected central hearing loss. This study's data sugg est that otoacoustic emissions when combined with ABR can provide a fr equency-specific evaluation of cochlear function and help determine th e anatomic site of a pathologic lesion.