Masking-Level Differences Obtained with a Pulsed Tonal Masker

Masking-Level Differences (MLDs) were obtained for the binaural condition N0Sπ with pulsed tonal signals masked by pulsed tones of the same frequency and duration. MLDs were measured relative to the condition N0S0. Frequencies tested were 250, 500, and 1000 Hz; the duration was 125 msec. Detection was measured with four values of the signal-to-masker phase, which for N0Sπ produced: (a) an interaural difference of time (Δt); (b) an interaural difference of intensity (ΔI); (c) Δt and ΔI both favoring the same ear (consonance); or (d) Δt and ΔI favoring opposite ears (dissonance). The magnitudes of the MLDs were largest for conditions of Δt alone, next largest for consonance, and least for dissonance and ΔI alone. The MLDs were positive in sign, in contrast to the negative MLDs that have previously been reported for similar stimuli. Data were shown to fit a lateralization model in which differential time-intensity trading occurs for consonance and dissonance.