Comparison of objective and subjective measures of cochlear compression in normal-hearing and hearing-impaired listeners

Among several behavioural methods for estimating the basilar membrane input/output function, the temporal masking curve is the most popular. Distortion product otoacoustic emissions provide an objective measure for estimating cochlear compression. However, estimates from both methods have been poorly correlated in previous studies. We hypothesise that this could be due to the interplay between generator and reflection components in the recorded otoacoustic emissions. Here, compression estimates obtained with the two methods were compared at three audiometric frequencies (1, 2, and 4 kHz) for 10 normal-hearing and 6 hearing-impaired listeners. Distortion-product otoacoustic emissions were evoked using continuouslyswept tones, to separate the generator component and investigate the corresponding compressive characteristic. For hearing imapired listeners, the estimates from the two methods were highly correlated.