Spatial Effects in Speech Perception in the Absence of Spatial Competition

Abstract

Two synthetic speech syllables, differing in pitch, were presented over one loudspeaker situated at one of the following azimuths: 0° (in front of the subject); 45°, 90°, and 135° to the left or to the right; and 180°. The subject's task was to report the high-pitch syllable. The pattern of performance can be described in terms of two component effects: a decreasing anterior—posterior gradient, and right-side advantage. Competition between messages from one direction only appears to be as effective in determining auditory spatial effects as competition between spatially distinct sources.