Perstimulatory Loudness Adaptation: The Effect of Comparison-Signal Duty Cycle

Using a double-staircase method, perstimulatory loudness adaptation was measured on a group of normal-hearing listeners for a variety of comparison-signal conditions. Signal on times ranging from 500 msec to 5 sec were employed in combination with duty cycles ranging from 10% to 8313%, resulting in a total of 22 different signal conditions. Adapting and comparison signals were 1-kHz pure tones, with the adapting tone always presented at 50 dB SPL. Mean data revealed that the duty cycle of the comparison signal had no systematic effect on adaptation in the test ear. This finding does not lend support to the previous assumption by Stokinger et al. [J. Acoust. Soc. Amer. 51, 602–607 (1972)] that there was a direct relationship between the duty cycle of the comparison signal and the amount of adaptation. [Work supported by the Research and Education Committee, Oklahoma City V. A. Hospital, under Project No. 20-69.]