ABSTRACT
The discrimination of broadband signals has been the focus of much research, owing in part to the interest in speech and other meaningful signals. Discriminating changes in sound level at individual frequencies is a rudimentary auditory ability, but one that is necessary for normal processing of speech and many natural sounds. Many psychoacoustic studies of hearing impairment have therefore focused on level discrimination of pure tones in quiet and in noise. Conditioned-on-a-single-stimulus (COSS) analysis has been widely applied to estimate the relative weight or reliance that normal-hearing listeners give to individual frequencies of a complex signal in detection and discrimination tasks. Normal-hearing listeners performed significantly more poorly in this task compared to the earlier task. COSS analysis provides a means whereby the effect of hearing loss on the weights given to particular frequencies can be assessed independently of its effect on sensitivity.
