Reaction Time as a Measure of Threshold and Suprathreshold Hearing. I. Normal Man and Monkey

Abstract

Reaction time to auditory stimuli has been suggested as a measure of loudness in nonverbal animals [Stebbins, J. Exp. Anal. Behav. 9, 135 (1966)]. The reaction time task can also be used to measure threshold. We have compared the relationship of this measure to other psychophysical measures of loudness and threhsold hearing in man, and have compared hearing in man and monkey under similar experimental conditions. Absolute sensitivity functions derived from human reaction time data closely matched clinical threshold measures and were an average of 5 dB above thresholds measured by a forced-choice method. Human equal-reaction time contours matched closely equal-loudness contours derived in the same subject by loudness matching. The human and monkey equal-reaction time contours are similar throughout the overlapping hearing range of the two species. The results of this study support the suggestion that response latency can be used as a measure of threshold hearing and loudness and have application to the study of mechanisms underlying hearing in the animal model. [Work supported by PHS Grants NS 08181, RR 00166, NS 50637, and NS 05082.]