Psychophysical Two-tone Suppression as a Function of Input Level for F₂/f₁>1.0

Psychophysical two-tone suppression was measured in three normal-hcaring young adults using the pulsation-threshold technique. The primary objective was to study the effect of L• on psychophysical twotone suppression for f2/f• > 1.0. Measurements were obtained at low and mid frequencies and for input levels ranging from 40 through 85 dB SPL. For f• --1000 or 2000 Hz, suppression i creased initially with L• and then decreased for L• _> 55 to 70 dB SPL. For f• = 500 Hz, however, suppression i creased monot0nically throughout he range of L• values examined. These findings are explained by assuming that forf• _> 1000 Hz the nonlinear mechanism responsible for two-tone suppression isvery susceptible to reversible dysfunction produced by the presentation of high-intensity stimuli.