FREQUENCY-SPECIFIC IDENTIFICATION OF HEARING-LOSS USING TRANSIENT-EVOKED OTOACOUSTIC EMISSIONS TO CLICKS AND TONES

Transient-evoked otoacoustic emissions (TEOAE) to clicks and to 500- a nd 2000-Hz brief tones were measured in 72 normal-hearing and hearing- impaired subjects (86 ears). The TEOAE's reproducibility parameter was used for the analyses. The purpose of the investigation was to determ ine which stimuli best predicted the presence of sensorineural hearing loss in a frequency-specific manner at 500, 1000, 2000, and 4000 Hz. Analyses of the TEOAEs filtered into frequency-specific bands showed t hat separation of normal and impaired ears at 1000, 2000 and 4000 Hz w as best achieved by TEOAEs evoked by clicks. Identification of hearing loss al 500 Hz was best obtained using 500-Hz tone-evoked TEOAEs filt ered using a band centered at 500 Hz. Octave- and half-octave-wide ban ds identified hearing loss equally well. An analysis sweep time of 20 ms provided slightly better results compared to 30 ms, except for 500 Hz, where the 30-ms sweep time slightly improved the identification of hearing loss. Increases in the audiometric criterion did not yield be tter test performance once hearing loss exceeded 20 dB HL. The finding s from this study suggest that the combination of bandpass-filtered TE OAEs to clicks and TEOAEs to 500-Hz tones identifies with reasonable a ccuracy ears with sensorineural hearing loss at 500, 1000, 2000, and 4 000 Hz.