Moore B C
J Acoust Soc Am. 1981 Jul;70(1):62-8. doi: 10.1121/1.386582.
Forward-masked thresholds for 1-kHz sinusoidal signals were measured as a function of the bandwidth of a noise masker centered at 1 kHz, using a two-interval forced-choice technique. The noise spectrum level was 40 dB SPL/Hz, and noise bandwidth was varied from 50 to 1600 Hz. In experiment I signal duration was varied, with a fixed offset-onset time of 5 ms between masker and signal. For the shortest signal (5 ms) threshold at first increased with increasing bandwidth and then decreased. As signal duration increased, the bandwidth at which maximum masking occurred (the rollover bandwidth) decreased, and for the longest signal (45 ms) maximum masking occurred for the narrowest bandwith tested. In experiment II the silent interval between masker and signal was varied, for a signal of 5-ms duration. Again threshold at first increased with noise bandwidth, and then decreased. However, the rollover bandwidth decreased with increasing silent interval, and threshold varied less with bandwidth. In experiment III signal duration was varied for a fixed offset-offset time of 50 ms between masker and signal. Changes in threshold with noise bandwidth were small, except for the longest signal (45 ms) for which threshold increased markedly at the narrowest bandwidth used. For the wider nose bandwidths, threshold decreased gradually with increasing signal duration, whereas for the narrowest noise bandwidth, threshold increased with increasing duration. It is argued that interactions of excitation and suppression within the internal representation of the masker influence the results, but at least two other factors, detection of energy splatter in the spectrum of the signal and the presence or absence of quality differences between masker and signal, have a powerful influence.
使用两间隔强迫选择技术，测量了1kHz正弦信号的前向掩蔽阈值，该阈值是作为以1kHz为中心的噪声掩蔽器带宽的函数。噪声频谱级为40dB SPL/Hz，噪声带宽在50至1600Hz之间变化。在实验I中，信号持续时间发生变化，掩蔽器与信号之间的固定起始-偏移时间为5ms。对于最短信号（5ms），阈值首先随带宽增加而增加，然后降低。随着信号持续时间增加，出现最大掩蔽的带宽（翻转带宽）减小，对于最长信号（45ms），在测试的最窄带宽处出现最大掩蔽。在实验II中，对于持续时间为5ms的信号，掩蔽器与信号之间的静音间隔发生变化。同样，阈值首先随噪声带宽增加，然后降低。然而，翻转带宽随静音间隔增加而减小，并且阈值随带宽变化较小。在实验III中，对于掩蔽器与信号之间固定的50ms偏移-偏移时间，信号持续时间发生变化。除了最长信号（45ms）在使用的最窄带宽处阈值明显增加外，阈值随噪声带宽的变化很小。对于较宽的噪声带宽，阈值随信号持续时间增加而逐渐降低，而对于最窄的噪声带宽，阈值随持续时间增加而增加。有人认为，掩蔽器内部表征中兴奋与抑制的相互作用影响了结果，但至少还有其他两个因素，即信号频谱中能量飞溅的检测以及掩蔽器与信号之间是否存在质量差异，具有强大的影响。
