Kidd G, Uchanski R M, Mason C R, Deliwala P S
Department of Communication Disorders, Boston University, Massachusetts 02215.
J Acoust Soc Am. 1993 Feb;93(2):1028-37. doi: 10.1121/1.405551.
Several experiments are described in which the task of the observer was to detect an intensity increment to the center tone of a narrow-band, multitone complex. The sound-pressure levels of the stimuli were equated, then randomized, so that listeners could not detect the signal by using level cues. The primary experimental variables were the number of tones in the masker spectrum, the level of the center tone or "pedestal" relative to the other tones, the center frequency and the sound-pressure level. Both "random-phase" and "fixed-phase" conditions (referring to whether the pattern of starting phases of the nonsignal tones was chosen randomly on every presentation or was held constant throughout each trial and block of trials) were tested. Although no simple detection strategy appeared to account for all of the results, the most plausible explanation for performance in most conditions was that the listeners were able to discriminate between sounds based on subtle differences in the amplitude envelopes of the waveforms.
描述了几个实验，其中观察者的任务是检测窄带多音复合体中心音的强度增量。刺激的声压级被等同，然后随机化，以便听众无法通过使用电平线索来检测信号。主要的实验变量是掩蔽频谱中的音调数量、中心音或“基座”相对于其他音调的电平、中心频率和声压级。测试了“随机相位”和“固定相位”条件（指非信号音调的起始相位模式是在每次呈现时随机选择还是在每个试验和试验块中保持不变）。尽管没有简单的检测策略似乎能解释所有结果，但在大多数情况下，对表现最合理的解释是听众能够根据波形幅度包络的细微差异来区分声音。
