Study of Per- and Poststimulatory Fatigue in Pitch Perception

Abstract

While changes and recovery in loudness sensitivity have been studied over time by many investigators, changes in the perception of pitch have been observed only at discrete time intervals and changes during these intervals can only be attributed to normal variation or error. No graphic display of an observer's pitch judgments over time has been available for inspection under the usual psychophysical procedures. The method used in this study permitted the continuous recording of the subjects' perception of pitch over time under perstimulatory and poststimulatory conditions. In Expt. 1, pitch perception was studied under per- and poststimulatory fatigue with 60 and 90 dB sensation-level signals at 250, 500, 1500, 2500, and 4500 Hz. In Expt. 2, pitch perception was examined after stimulation of 100 dB SL for 10 min at the above frequencies. In Expt. 3, a fatiguing stimulus at 750 Hz was presented for two minutes at 120 dB SPL. Pitch perception was then studied at adjacent frequencies: 550, 650, 850, 950 Hz. No systematic change in pitch perception was observed under any of the experimental conditions. Since these findings conflict with similar studies, special attention was given to procedural and theoretical reasons for the discrepancies.