Effects of target phase in narrow-band frozen noise detection data

Abstract

Hit and false alarm rates were estimated for detection of a 500-Hz tone target in each often samples of 1/3-oct noise centered at 500 Hz for both NoSπ and NoSo conditions. The effects of target phase (0° and 90°) on hit rate were investigated for three subjects. Results for this narrow-band case were similar to previously reported results for wideband maskers [Gilkey et al., J. Acoust. Soc. Am. 78, 1207–1219 (1985)]. Two differences were noted. First, for NoSπ conditions, the effect of signal phase was not significant for the narrow-band maskers, whereas a small effect was reported for wideband maskers. Second, no significant correlation was observed between NoSo and NoSπ results across masker waveforms for hit and false alarm rates, whereas significant correlations for both rates were reported for the wideband experiment. The lack of effect of target phase on hit rate in the narrow-band NoSπ condition is inconsistent with models based on lateral position but consistent with the EC model and with models using the sum of the squares of interaural time and intensity differences. [Work supported by NIH.]