DISTORTION-PRODUCT OTOACOUSTIC EMISSIONS IN THE ELDERLY

Clinical interest in otoacoustic emissions (OAEs) is increasing. These can be elicited rapidly in a number of test paradigms that reflect th e functional status of the outer hair cells of the organ of Corti. Dis tortion product otoacoustic emissions (DPOEs) have been well described in infants, and adults, but not in the elderly. The value of DPOE tes ting as a means of objective assessment of cochlear function is still being studied. The authors obtained DPOEs in 129 ears of 71 elderly vo lunteer subjects (age 56-93 yr) and in 16 ears of eight young adults ( age 19-26 yr) with normal pure-tone thresholds (PTTs). The relation be tween DPOEs and PTTs, as expressed by the r2 statistic, was 0.18, 0.46 , and 0.30 at 1, 2, and 4 kHz, respectively. Amplitudes of DPOEs did n ot decrease significantly with age, when adjusted for PTTs. Sensitivit y and specificity, receiver operating characteristic curves, as well a s posterior probabilities were analyzed to elucidate the relation betw een DPOEs and PTTs. At 2 kHz 90 percent of ears with PTTs 40 dB HL or less exhibited DPOEs of -4 dB SPL or greater, and all ears with PTTs g reater than 40 dB HL had either no measurable DPOEs or DPOE amplitude less than 4 dB SPL.