A psychophysiological study of auditory illusions of approach and withdrawal in the context of the perceptual environment

Auditory perception of the depth of space is based mainly on spectral and amplitude changes of sound waves originating from the sound source and reaching the listener. The perceptive illusion of movement of an auditory image caused by changes in amplitude and/or frequency of the signal tone emanating from an immobile loudspeaker was studied. Analysis of data obtained from the participants revealed the diapason of combinations of amplitude and frequency changes for which the movement direction was perceived similarly by all participants, despite significantly different movement assessment criteria. Additional auditory and visual information of the conditions of radial movement (near or far fields) determined listeners' interpretation of changes in the signal parameters. The data obtained about the perception of approach and withdrawal models are evidence of the fact that the principal cues of the perception of the distance of immobile sound sources manifests similarly to that of an auditory image moving along a radial axis.