Bernstein L R, Trahiotis C, Hyde E L
Department of Surgery (Otolaryngology), University of Connecticut Health Center, Farmington 06030, USA.
J Acoust Soc Am. 1998 Apr;103(4):2069-78. doi: 10.1121/1.421378.
Detection thresholds for either 500-Hz tones or 4-kHz tones were measured for a group of 19 listeners utilizing the interaural configurations NoSo and NoS pi. Both broadband (100-8500 Hz) noises and narrow-band (50-Hz-wide) noises served as maskers. In addition, direct measures of the listeners' sensitivities to changes in interaural temporal differences (ITDs) and interaural intensitive differences (IIDs) were measured using 400-Hz-wide noises centered at 500 Hz or 4 kHz. A rather large range of inter-individual differences in threshold was observed for 4-kHz tonal signals masked by narrow-band noise in the NoS pi configuration. This result is consistent with several sets of data from our previous experiments conducted over more than a decade. A broad range of thresholds was also obtained for 500-Hz tonal signals masked by narrow-band noise in the NoS pi configuration. This outcome, coupled with the fact that the use of a broadband masker did not yield a large distribution of thresholds for the detection of a 500-Hz tone masked by a broad band of noise, suggests that it is the use of a narrow-band masker, per se, that results in a large range of thresholds. Statistical analyses revealed that thresholds in the NoS pi detection tasks were not highly correlated with thresholds measured in the ITD- and the IID-discrimination tasks. Nevertheless, the five listeners who were the most sensitive in the narrow-band NoS pi detection and the five listeners who were the least sensitive in the narrow-band NoS pi detection tasks were those who were the most and least sensitive, respectively, to changes in ITDs and to changes in IIDs.
利用NoSo和NoS π这两种双耳配置，对一组19名听众测量了500赫兹纯音或4千赫兹纯音的检测阈值。宽带（100 - 8500赫兹）噪声和窄带（50赫兹宽）噪声均用作掩蔽音。此外，使用以500赫兹或4千赫兹为中心的400赫兹宽噪声，直接测量了听众对双耳时间差（ITD）和双耳强度差（IID）变化的敏感度。在NoS π配置中，观察到窄带噪声掩蔽4千赫兹音调信号时，个体阈值存在相当大的差异范围。这一结果与我们过去十多年进行的几组实验数据一致。在NoS π配置中，窄带噪声掩蔽500赫兹音调信号时也获得了广泛的阈值范围。这一结果，再加上使用宽带掩蔽音并未产生用于检测宽带噪声掩蔽的500赫兹音调的大范围阈值分布这一事实，表明正是窄带掩蔽音本身导致了大范围的阈值。统计分析表明，NoS π检测任务中的阈值与ITD辨别任务和IID辨别任务中测量的阈值并非高度相关。然而，在窄带NoS π检测中最敏感的五名听众和在窄带NoS π检测任务中最不敏感的五名听众，分别是对ITD变化和IID变化最敏感和最不敏感的人。
