Binaural masking of tones by tones: Effects of uncertainty regarding the phase angle of addition of signal to masker

This paper compares performance in tone-on-tone coherent binaural masking for conditions with and without listener knowledge concerning the phase angle of addition of the signal to the masker. Uncertainty was introduced by randomizing the four phase angles: 0, 45, 90, and 135 deg. Stimuli were 125-msec tone bursts at 250 Hz. The results showed a clear decrement in detection performance under the uncertainty condition at 135 deg, with weaker evidence for decrements at other phase angle values. This supports the assumption that the decision process was a function of the phase angle in previous studies of binaural tone-on-tone masking.