Semal C, Demany L
Laboratoire de Psychoacoustique, Université de Bordeaux, France.
J Acoust Soc Am. 1993 Sep;94(3 Pt 1):1315-22. doi: 10.1121/1.408159.
In four related experiments, subjects had to discriminate between the presence or absence of a frequency difference between two pure tones separated by 4.3 s. The interference effects of other tones (I), inserted during the retention interval, were investigated. A previous study [C. Semal and L. Demany, J. Acoust. Soc. Am. 89, 2404-2410 (1991)] had shown that subjects' performance strongly depended on the pitch relations between the test tones and the I tones, but not on the spectral composition of the I tones. This suggested that the mnemonic system processing pitch is deaf to sharpness of timbre. In the present study, the I tones could differ or not from the test tones in intensity (by +/- 6 or 15 dB) or in amplitude envelope (periodic as well as aperiodic envelopes were used). It was found that such differences had very little effect on performance, suggesting that the mnemonic system processing pitch is deaf to loudness and to dynamic aspects of timbre. However, for I tones with a dense spectrum in the vicinity of the test tones' frequencies, widening the I tones' spectrum improved performance, probably because this spectral widening decreased the salience of the I tones' pitches.
在四项相关实验中，受试者必须辨别两个间隔4.3秒的纯音之间是否存在频率差异。研究了在保持间隔期间插入的其他音调（I）的干扰效应。先前的一项研究[C. 塞马尔和L. 德马尼，《美国声学学会杂志》89, 2404 - 2410 (1991)]表明，受试者的表现强烈依赖于测试音调和I音调之间的音高关系，而不依赖于I音调的频谱组成。这表明处理音高的记忆系统对音色的清晰度不敏感。在本研究中，I音调在强度（相差±6或15分贝）或幅度包络（使用了周期性和非周期性包络）方面可能与测试音调不同，也可能相同。结果发现，这种差异对表现影响很小，这表明处理音高的记忆系统对响度和音色的动态方面不敏感。然而，对于在测试音调频率附近具有密集频谱的I音调，拓宽I音调的频谱会提高表现，这可能是因为这种频谱拓宽降低了I音调音高的显著性。
