A review of the effectiveness of otoacoustic emissions for evaluating hearing status after newborn screening.

OBJECTIVES The purpose of this study was to give a brief review of the effectiveness of otoacoustic emissions for getting frequency-specific information about a hearing-loss problem in newborns after hearing screening. Especially, the advantages of distortion-product otoacoustic emissions (DPOAE) over transiently evoked otoacoustic emissions (TEOAEs) are described. DATA SOURCES Approximately 186 ears of 104 children aged between 76 days and 15 years and 436 ears of adults with normal hearing and sensory hearing loss. METHODS Extrapolated DPOAE I/O-functions at frequencies between 1.5 and 6 kHz were obtained in the children for assessing the hearing loss and for differentiating between a transitory sound-conductive hearing loss and a persisting cochlear hearing loss. For getting information on the test time needed, measurements were performed in the adult patients. RESULTS DPOAE thresholds derived from extrapolated DPOAE I/O-functions (DPOAE audiograms) are closely related to behavior audiometric thresholds and can be used for determining characteristic quantities of the cochlear-impaired ear. A DPOAE audiogram can be obtained in a couple of minutes. DPOAE audiograms are able to reveal a transitory sound-conductive hearing loss because of Eustachian tube dysfunction and/or amniotic fluid in the tympanic cavity or to confirm a persisting cochlear hearing loss because of outer hair cell impairment in babies with a reference result in newborn hearing screening. CONCLUSION DPOAE audiograms provide a tool for a fast automated frequency-specific and quantitative evaluation of a mild or moderate hearing in follow-up diagnosis.