Loudness and the acoustic reflex: cochlear-impaired listeners.

The relationships among most comfortable listening level (MCL), loudness discomfort level, and the acoustic reflex (AR) to speech were studied on cochlear-impaired listeners using earphones and sound field conditions. Recorded sentence materials were presented monaurally in quiet and in the sound field in the presence of 55 dB SPL cafeteria noise. Both unaided and aided sound field testing were done. The results indicated that the MCL and AR fell at approximately the same intensities under all test conditions, whereas the LDL occurred at approximately 18 dB higher intensity. The MCL was elevated by the presence of noise, whereas the AR remained invariant. Also, the AR occurred below the level predicted by the loudness function. The results tend to indicate that although the AR is highly correlated with MCL in cochlear-impaired listeners a cause and effect relationship may not exist.