Binaural integration of tonal patterns

Abstract

It has been argued that a limitation exists in the rate at which we can switch attention between ears in monitoring auditory information. Listeners identified melodic configurations formed by rapid sequences of tones. When these sequences were presented diotically, near perfect performance was obtained. Yet when they were presented with the tones switching between ears, performance was close to chance. However when these same dichotic sequences were accompanied by a drone that always occurred in the ear opposite to the ear receiving a component of the melody, performance rose dramatically, approaching that in the diotic condition. This improvement in performance could not have been due to processing the harmonic relationships between melody and drone, since when instead the drone occurred in the same ear as the component of the melody, performance was at chance. It is concluded that difficulties in binaural integration observed under some conditions are due, not to a processing limitation, but to a strategy that is invoked under certain conditions to prevent confusion in monitoring individual sound sources.