Kidd G R, Watson C S
Department of Speech and Hearing Sciences, Indiana University, Bloomington 47405, USA.
J Acoust Soc Am. 1996 Jan;99(1):553-66. doi: 10.1121/1.414513.
The ability to detect frequency changes in transposed sequences of tones was examined in a series of seven experiments. Listeners were asked to judge which of two transposed (i.e., frequency-shifted) comparison patterns preserved the sequence of relative frequencies presented in a preceding standard pattern. The task was performed with five-tone and two-tone patterns under conditions of high and minimal pattern uncertainty. Regardless of pattern length or level of uncertainty, frequency discrimination thresholds for a change in the relative frequency of a single tone were considerably higher when patterns were transposed than when they were not. There was a tendency for performance to worsen with increasing degrees of transposition (primarily under high uncertainty) but most of the detrimental effects of transposition occurred within the first two semitones of transposition. Minimal uncertainty testing resulted in large improvements with five-tone patterns (as much as one order of magnitude), but there was no effect of level of uncertainty on performance with two-tone patterns. Thresholds for changes in two-tone patterns were similar to (although slightly higher than) those for five-tone patterns under minimal-uncertainty testing. This pattern of results reveals that the effects of stimulus complexity (sequence length) and pattern familiarity (level of uncertainty) on relative-frequency discrimination are quite similar to the effects of these variables on absolute-frequency discrimination.
在一系列七个实验中，研究了检测音调转置序列中频率变化的能力。要求听众判断两个转置（即频率偏移）的比较模式中哪一个保留了先前标准模式中呈现的相对频率序列。该任务在高音调模式不确定性和最小音调模式不确定性条件下，使用五音调和双音调模式进行。无论模式长度或不确定性程度如何，当模式转置时，单个音调相对频率变化的频率辨别阈值比不转置时要高得多。随着转置程度的增加（主要在高不确定性条件下），表现有变差的趋势，但转置的大部分有害影响发生在转置的前两个半音内。最小不确定性测试使五音调模式有了大幅改善（多达一个数量级），但不确定性程度对双音调模式的表现没有影响。在最小不确定性测试下，双音调模式的变化阈值与五音调模式的阈值相似（尽管略高）。这种结果模式表明，刺激复杂性（序列长度）和模式熟悉度（不确定性程度）对相对频率辨别的影响与这些变量对绝对频率辨别的影响非常相似。
