Department of Psychology, University of York, York YO10 5DD, United Kingdom.
J Acoust Soc Am. 2010 May;127(5):3026-37. doi: 10.1121/1.3365252.
In a series of experiments, Semal and Demany [(2006). J. Acoust. Soc. Am. 120, 3907-3915] demonstrated that some normally hearing listeners are unable to determine the direction of small but detectable differences in frequency between pure tones. Unlike studies demonstrating similar effects in patients with brain damage, the authors used stimuli in which the standard frequency of the tones was highly uncertain (roved) over trials. In Experiment 1, listeners were identified as insensitive to the direction of pitch changes using stimuli with frequency roving. When listeners were retested using stimuli without roving in Experiment 2, impairments in pitch-direction identification were generally much less profound. In Experiment 3, frequency-roving range had a systematic effect on listeners' thresholds, and impairments in pitch-direction identification tended to occur only when the roving range was widest. In Experiment 4, the influence of frequency roving was similar for continuous frequency changes as for discrete changes. Possible explanations for the influence of roving on listeners' insensitivity to pitch-change direction are discussed.
在一系列实验中，Semal 和 Demany [(2006). J. Acoust. Soc. Am. 120, 3907-3915] 证明，一些听力正常的听众无法确定纯音之间小但可检测到的频率差异的方向。与在脑损伤患者中证明类似效果的研究不同，作者使用了在试验中标准频率高度不确定（漫游）的刺激。在实验 1 中，使用频率漫游的刺激来识别对音高变化方向不敏感的听众。当在实验 2 中使用没有漫游的刺激对听众进行重新测试时，音高方向识别的障碍通常要小得多。在实验 3 中，频率漫游范围对听众的阈值有系统影响，并且只有在漫游范围最宽时，音高方向识别的障碍才会发生。在实验 4 中，频率漫游对连续频率变化和离散变化的影响相似。讨论了漫游对听众对音高变化方向不敏感的影响的可能解释。
