Interaural Phase Effects in the Masking of Signals of Different Durations

Abstract

The detectability of a pulsed, 250-cps sinusoid in noise was measured under three interaural phase conditions and at three durations. The conditions were (1) signal and noise in one ear only, SmNm, (2) signal in one ear and the same in-phase noise in both ears, SmN0, (3) signal in both ears, but with a 180° phase difference, and the same in-phase noise in both ears, SπN0. The detectability of the signal was about 9 dB better in Condition 2 than in Condition 1, and about 7 dB better in Condition 3 than in Condition 2. The difference in detectability is slightly dependent on signal duration, the largest difference appearing at the shortest duration. The psychometric functions were essentially the same in all conditions, except for an attenuation constant. The results are contrasted with two theories used to account for the binaural effects; some discrepancy between both theories and the results are noted.