Tone-on-Tone Masking for Three Binaural Listening Conditions

The M0-Sm, M0-SΠ and M0-S0 conditions were investigated in a tone-on-tone binaural masking paradigm. Both the signal and the masker were gated sinusoids of the same frequency, duration, and rise-decay time. The data obtained from the two dichotic conditions (M0-SΠ and M0-Sm) indicate that, at low frequencies, detection is based entirely on the interaural phase and intensive differences present in the waveforms. At high frequencies, the interaural phase difference was no longer usable as a cue; thus, detection was the same as in the M0-S0 condition. The interaural intensive difference required for detection was the same at all frequencies. The masking-level differences (MLDs re M0-S0) obtained in the M0-Sm condition were smaller than those obtained in the M0-SΠ condition and were negative in some situations. The data are in agreement with the predictions of the lateralization model proposed by Hafter and Carrier [J. Acoust. Soc. Amer. 47, 1041-1047 (1970)].