Peters R W, Moore B C, Glasberg B R
Department of Medical Allied Health Professions, School of Medicine, University of North Carolina, Chapel Hill 27599, USA.
J Acoust Soc Am. 1995 Jun;97(6):3791-9. doi: 10.1121/1.412394.
Thresholds for the detection of decrements in level of sinusoidal signals were measured as a function of decrement duration, level (25, 40, 55, and 70 dB SPL) and frequency (250, 1000, and 4000 Hz) in eleven normally hearing subjects. Thresholds for detecting a brief increment in level were also measured. The sinusoids were presented in a background noise intended to mask spectral splatter associated with the decrement or increment. Performance tended to worsen with decreasing frequency, for all decrement durations and for increment detection. Performance also worsened with decreasing level. The results were analyzed using a model consisting of a compressive nonlinearity, a sliding temporal integrator, and a decision device. The analysis indicated that the worsening in performance with decreasing frequency and decreasing level can be attributed partly to increases in the equivalent rectangular duration (ERD) of the temporal integrator, but mainly to changes in the efficiency of the detection process following the temporal integrator; at lower frequencies and levels a larger change is required at the output of the integrator for threshold to be reached. At each frequency, the ERD was relatively invariant with level for levels more than about 20 dB above the absolute threshold.
在11名听力正常的受试者中，测量了作为递减持续时间、声级（25、40、55和70 dB SPL）和频率（250、1000和4000 Hz）函数的正弦信号电平递减检测阈值。还测量了检测电平短暂增加的阈值。正弦波呈现于背景噪声中，旨在掩盖与递减或递增相关的频谱散射。对于所有递减持续时间和递增检测，随着频率降低，性能往往会变差。随着声级降低，性能也会变差。使用由压缩非线性、滑动时间积分器和决策装置组成的模型对结果进行了分析。分析表明，随着频率降低和声级降低，性能变差部分可归因于时间积分器等效矩形持续时间（ERD）的增加，但主要归因于时间积分器之后检测过程效率的变化；在较低频率和声级下，积分器输出需要更大的变化才能达到阈值。在每个频率下，对于高于绝对阈值约20 dB以上的声级，ERD相对不随声级变化。
