Dye R H, Yost W A, Stellmack M A, Sheft S
Parmly Hearing Institute, Loyola University, Chicago, Illinois 60626.
J Acoust Soc Am. 1994 Nov;96(5 Pt 1):2720-30. doi: 10.1121/1.411278.
A two-dimensional stimulus classification paradigm was used to assess the extent to which listeners' processing of interaural delays at low frequencies is spectrally analytic or synthetic. Listeners were presented with a 753-Hz target with an interaural delay that varied from trial to trial, taking on one of ten values, five leading to the left ear and five leading to the right. A 553-Hz distractor component was simultaneously presented, with its interaural delay also presented at one of ten different values. During a block of 100 trials, each of the possible combinations of target and distractor delay was presented once, and only once, in a random order. Listeners were instructed to make left-right judgments based on the target delay. Each condition was repeated ten times, and the slopes of the best linear boundaries between left and right responses were used to derive the relative weights given to the target and distractor in judgments of laterality. Six of the nine listeners gave increasing weight to the target as the duration of the signals was increased from 25 or 50 to 400 ms. Three listeners showed little change with duration; one consistently gave equal weight to the target and distractor, two consistently gave greater weight to the target than to the distractor. The utility of classification paradigms in the study of multidimensional acoustic signals is discussed.
采用二维刺激分类范式来评估听众对低频双耳延迟的处理在频谱分析或合成方面的程度。向听众呈现一个753赫兹的目标音，其双耳延迟在每次试验中都有所变化，有十个值可供选择，其中五个值会使声音先到达左耳，五个值会使声音先到达右耳。同时呈现一个553赫兹的干扰成分，其双耳延迟也有十个不同的值可供选择。在100次试验的一个组块中，目标音和干扰音延迟的每种可能组合都以随机顺序呈现一次，且仅呈现一次。要求听众根据目标音延迟做出左右判断。每个条件重复十次，利用左右反应之间最佳线性边界的斜率来得出在判断声音位置时给予目标音和干扰音的相对权重。随着信号持续时间从25毫秒或50毫秒增加到400毫秒，九名听众中有六名给予目标音的权重增加。三名听众的权重随持续时间变化不大；一名听众始终给予目标音和干扰音相等的权重，两名听众始终给予目标音的权重大于干扰音。讨论了分类范式在多维声学信号研究中的效用。
