TOWARD OPTIMIZING THE CLINICAL UTILITY OF DISTORTION-PRODUCT OTOACOUSTIC EMISSION MEASUREMENTS

This study examined the effect of primary stimulus level on the abilit y of distortion product otoacoustic emission (DPOAE) measurements to s eparate normal-hearing from hearing-impaired ears. Complete I/O functi ons were obtained for nine f(2) frequencies on 210 people approximatel y evenly divided between normal hearing and hearing impaired. Clinical decision theory was used to assess both DPOAE amplitudes and DPOAE th reshold as diagnostic indicators of hearing status. Moderate level pri mary stimuli elicited responses that separated normal from impaired be tter than either lower level or higher level stimuli. The two populati ons were differentiated for all frequencies above 500 Hz by DPOAE ampl itude, given primary levels, L(1) and L(2), of 65 and 55 dB SPL. DPOAE threshold performed equally well, but threshold ambiguity in noise an d longer testing times make it a less suitable DPOAE measure to use di agnostically. (C) 1996 Acoustical Society of America.