Strickland E A, Viemeister N F
Department of Psychology, University of Minnesota, Minneapolis 55455, USA.
J Acoust Soc Am. 1996 Jun;99(6):3638-46. doi: 10.1121/1.414962.
Thresholds for detection of sinusoidal amplitude modulation at a signal modulation frequency were measured in the presence of a masker modulation frequency, with broadband noise carriers. Broad tuning for modulation frequency was observed. For maskers half or twice the signal frequency, thresholds depended on the relative phases of the signal and masker. These results were used to determine what aspects of envelopes listeners might be using in making decisions. Simulations were performed using an envelope detector model, consisting of bandpass filtering, half-wave rectification, and low-pass filtering. Decisions were based on envelope statistics that have been used to predict other data. These statistics were (1) rms power, (2) ratio of maximum to minimum amplitude (max/min), (3) crest factor, (4) fourth moment, and (5) average slope. The max/min statistic was successful at predicting the major trends in the data, without requiring the presence of channels tuned to modulation frequency.
在存在掩蔽调制频率且载波为宽带噪声的情况下，测量了信号调制频率下正弦幅度调制的检测阈值。观察到调制频率的宽调谐现象。对于频率为信号频率一半或两倍的掩蔽音，阈值取决于信号和掩蔽音的相对相位。这些结果被用于确定听者在做出决策时可能使用的包络的哪些方面。使用一个包络检测器模型进行了模拟，该模型由带通滤波、半波整流和低通滤波组成。决策基于已用于预测其他数据的包络统计量。这些统计量包括：(1)均方根功率，(2)最大与最小幅度之比（max/min），(3)波峰因数，(4)四阶矩，以及(5)平均斜率。max/min统计量成功地预测了数据中的主要趋势，而无需存在调谐到调制频率的通道。
