Perception of Loudness at Suprathreshold Levels during Visual Stimulation

Abstract

Six observers engaged in an alternate binaural loudness balance (ABLB) task utilizing the method of adjustment to explore the perception of loudness of a 300-msec-duration 1-kHz auditory stimulus at 20 and 50 dB SL's. Conditions utilized were no visual stimulation during ABLB, visual stimulation in synchrony with the standard auditory stimulus during ABLB, and visual stimulation in synchrony with the comparison auditory stimulus during ABLB. The visual stimulus was a short-duration stroboscopic light flash. The data indicated that sensory interaction in terms of visual facilitation of auditory loudness does occur and is more apparent at higher rather than lower SL's. Observers adjusted the comparison stimulus to a higher SL when the visual stimulus was associated with the standard stimulus than they did when the visual stimulus was associated with the comparison stimulus. The magnitude of this statistically significant difference was 7 dB and it implies that information presented to the visual sensory modality can affect the perception of the magnitude of information presented to the auditory sensory modality. [Work supported by University of Wisconsin Graduate School.]