Reaction Time as a Measure of Suprathreshold Masking

Abstract

Reaction time (RT) to pure tones masked by white noise was determined with two observers. At least five noise intensities, covering a 0–80 dB SL range, were selected; the tone intensity range was similarly divided. Seven tone frequencies from 250 Hz to 8 kHz were investigated. Finger-withdrawal RTs to tone onset were taken on 30 successive light-cued trials at a given combination of frequency and tone and noise intensities, presented monaurally. Noise was present continuously; tone duration was 1 sec, and foreperiod was variable. Data were obtained for intensity pairs yielding less than 1 sec RTs. Noise intensities were run in increasing order; tone intensities varied randomly within a given noise level. At equal signal-to-noise ratios for a given frequency, functions relating RT to tone and noise intensity appeared similar. Equal RT contours showed threshold shifts as a function of noise intensity. Comparison of these results with threshold masking data illustrated the use of RT as a measure of suprathreshold masking.