Abstract:

One method for estimating the temporal resolution of the monaural auditory system is to measure the shortest silent gap, placed in a noise burst, that is detectable. An analog of this method was developed to estimate the temporal resolution of the binaural auditory system. The shortest burst of interaural-uncorrelated noise, placed between two bursts of interaural-correlated noise, that listeners could detect was measured. The spectrum level (40 dB SPL), bandwidth (100 Hz), and center frequency (250 to 1000 Hz) of the three bursts were the same. Its threshold duration depended upon center frequency: 6.5 ms at 250 Hz and 35 ms at 1000 Hz (silent-gap thresholds were 15 ms at 250 Hz and 13 ms at 1000 Hz). The interaural-correlation jnd was also measured: 0.03 at 250 Hz and 0.10 at 1000 Hz. The results were modeled using a Gaussian temporal window. Its duration is determined by both the threshold duration and the jnd: The values varied little with center frequency, i.e., 260 ms at 250 Hz and 230 ms at 1000 Hz. This lack of variation differs considerably from the variation of the experimental thresholds. The results are compatible with binaural temporal resolution being independent of center frequency.