Auditory motion aftereffects of low- and high-frequency sound stimuli

Abstract

Adaptation of listeners to approaching or receding sound stimuli continued for 5 s under free-field conditions. Motion of the adaptive and test sound stimuli was simulated by means of oppositely directed linear changes in the amplitude of the low- and high-frequency noises (0.05–1 and 3–20 kHz, respectively) from two stationary loudspeakers. In a group of eight subjects with normal hearing, the auditory motion after-effect of the approaching and receding sound stimuli was evaluated by integrated indices that characterized the shift of the psychometric curves in response to the test stimuli under various conditions of listening. The aftereffect occurs in the case when the spectral composition of the adaptive and test stimuli coincides. In response to the high-frequency stimuli, the effect of adaptation to both the approaching and receding sound stimuli was observed, while in response to the low-frequency stimuli, only the approach of stimuli caused an aftereffect. There was no radial motion aftereffect in the case of mismatching the spectral bands of the adaptive and test stimuli. Thus, the frequency selectivity was characteristic of the auditory aftereffect of adaptation to the approaching and receding sound stimuli.