Interaural Correlation and Loudness

Abstract

An extensive literature shows that when the same sound is presented to both ears rather than to just one, a phenomenon called binaural summation occurs (Reynolds and Stevens 1960), in which the overall loudness of a stimulus presented to both ears is greater. A much smaller literature on the effect of interaural correlation on binaural loudness indicates that it has no additional effect (Dubrovskii and Chernyak 1969; Dubrovskii et al. 1972). However, Culling et al. (2001) found that listeners judged a band of noise spectrally flanked by correlated noise as progressively louder as its interaural correlation decreased towards zero. Culling et al. attributed the effect to the mechanism of binaural unmasking (e.g. Durlach 1972; Culling and Summerfield 1995).