Centre for Applied Hearing Research, Department of Electrical Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
J Acoust Soc Am. 2013 Jan;133(1):350-64. doi: 10.1121/1.4768882.
The relative contributions of within-channel and across-channel processes to perceptual comodulation masking release (CMR) were investigated in the framework of an auditory processing model. A generalized version of the computational auditory signal processing and perception model [CASP; Jepsen et al., J. Acoust. Soc. Am. 124, 422-438 (2008)] was used and extended by an across-channel modulation processing stage according to Piechowiak et al. [J. Acoust. Soc. Am. 121, 2111-2126 (2007)]. Five experimental paradigms were considered: CMR with a broadband noise masker as a function of the masker spectrum level; CMR with four widely spaced flanking bands (FBs) varying in overall level; CMR with one FB varying in frequency and level relative to the on-frequency band (OFB); CMR with one FB varying in frequency; and CMR as a function of the number of FBs. The predictions suggest that at least three different mechanisms contribute to overall CMR in the considered conditions: (1) a within-channel process based on changes in the envelope characteristic due to the addition of the signal to the masker; (2) a within-channel process based on nonlinear peripheral processing of the OFB's envelope caused by the FB(s); and (3) an across-channel process that is robust across presentation levels but relatively small (2-5 dB).
在听觉处理模型的框架内，研究了通道内和通道间过程对感知共调掩蔽释放（CMR）的相对贡献。使用了一种广义的计算听觉信号处理和感知模型（CASP；Jepsen 等人，J. Acoust. Soc. Am. 124, 422-438（2008）），并根据 Piechowiak 等人的研究扩展了一个跨通道调制处理阶段。J. Acoust. Soc. Am. 121, 2111-2126（2007）。考虑了五种实验范式：作为掩蔽谱级函数的宽带噪声掩蔽的 CMR；总体水平变化的四个宽间隔侧翼带（FB）的 CMR；相对于频带（OFB）的频率和水平变化的一个 FB 的 CMR；频率变化的一个 FB 的 CMR；以及作为 FB 数量函数的 CMR。预测表明，在考虑的条件下，至少有三种不同的机制对整体 CMR 做出贡献：（1）基于由于信号添加到掩蔽器而导致的包络特征变化的通道内过程；（2）基于 FB 对 OFB 包络的非线性外围处理的通道内过程；（3）一种跨通道过程，该过程在呈现水平上具有稳健性，但相对较小（2-5dB）。
