Effect of Rise Time on Amplitude DL

The literature on rise time vs amplitude DL suggested need for an experiment in which the only stimulus parameter varied was rise time and in which the subjects could be expected to be performing as well as possible. The 20‐dB SL stimulus was a sine wave of 1000 or 4000 Hz. Its amplitude could be increased stepwise by calibrated small amounts, with exponential rise times of 10, 25, and 50 msec from a positive‐going zero crossing. A 2I temporal FC staircase, with feedback, was used. In three subjects, at both frequencies, median DL's were quite small: 0.25, 0.4, and 0.5 dB, at rise times of 10, 25, and 50 msec. Similarity of results at both frequencies agrees with evidence that at those frequencies, signal duration required for transition from click pitch to tone pitch is constant. This consistency may derive from a low‐pass property of the auditory system. [This research was supported in part by the Veterans Administration Hospital, Seattle, and the University of Washington, Psychophysics Research Program...