The Effects of Bimodal Presentation of Stimuli and Noise on Target Identification

Abstract

Abstract : Identification thresholds were measured for four targets which were presented on a CRT display or through earphones under 5 conditions: (1) auditory target with auditory noise; (2) visual target with visual noise; (3) auditory target with both visual and auditory noise; (4) visual target with both visual and auditory noise; and (5) both visual and auditory targets with both visual and auditory noise. Both visual and auditory thresholds were better when the auditory and visual targets were presented together than when either was presented alone. This was true whether the two stimuli were being increased in intensity simultaneously or whether the secondary stimuli was set at a constant level 1 to 4 dB below the baseline threshold.