The Influence of Interaural Phase Relations upon the Masking of Speech by White Noise

Abstract

Speech waves were presented binaurally to subjects with the waves in phase or out of phase at the 2 ears, while white noise waves were presented simultaneously with the waves in phase, out of phase, and random with respect to phase at the 2 ears. Intelligibility of speech was highest when the noise waves were in phase and the speech waves out of phase, second highest when the speech waves were in phase and the noise waves out of phase, lowest when both speech and noise waves were out of phase, second lowest when both were in phase, and intermediate when speech waves were presented with random phase noise waves. Observations with other interaural phase relations and with nonaural-binaural presentations of speech and noise are described. A significant improvement in reception when speech is heard through earphones in the presence of noise may be obtained by reversing the connections of one of the earphones. The significance of the results for the theory of masking is discussed.