Abstract
The clinical use of distortion product otoacoustic emissions (DPOAE) stems from the observation that the outer hair cells are the most vulnerable part of the cochlea, and damage to these cells is associated with hearing loss and loss of DPOAE. The purpose of this study is to evaluate the applicability of DPOAE in predicting hearing thresholds under clinical conditions. DPOAE measurements (L 1 = L 2 = 70 dB SPL, f 2 /f 1 = 1.20) of 219 hearing-impaired and normal hearing ears were analyzed. Recordings were acquired for DPOAE at 2 f 1 -f 2 varying from 635 to 4052 Hz. The detectability of DPOAE in hearing-impaired subjects exhibited a strong hearing threshold dependence. Receiver operating characteristic (ROC) analysis yielded the highest sensitivity and specificity for threshold levels of about 30 dB at low frequencies and for threshold levels of about 60 dB at high frequencies. In addition, the separability of groups with different hearing status was more reliable at high frequencies as compared to low frequencies. The DPOAE provide an objective assessment of cochlear function. However, prognosis of hearing thresholds on the basis of DPOAE measurements depends strongly on the test frequency and is associated with large errors. Hence, the clinical use of DPOAE in predicting hearing thresholds is limited.