载频水平对调幅掩蔽调谐的影响。
The effect of carrier level on tuning in amplitude-modulation masking.
机构信息
Department of Psychology, University of Minnesota, 75 East River Road, Minneapolis, Minnesota 55455, USA.
出版信息
J Acoust Soc Am. 2011 Dec;130(6):3916-25. doi: 10.1121/1.3658475.
The effect of carrier level on tuning in modulation masking was investigated for noise and tonal carriers. Bandwidths of the modulation filters, estimated from the masked detection thresholds using an envelope power spectrum model, were independent of level for the noise carrier but seemed to decrease with increasing level for the tonal carrier. However, the apparently sharper tuning could be explained by increased modulation sensitivity and modulation dynamic range with increasing level rather than improved modulation-frequency selectivity. Consistent with this interpretation, the addition of a high-pass noise with a level adjusted to maintain the same threshold for the detection of the signal modulation for each carrier level used eliminated the effect of level on tuning. Overall, modulation filters estimated from psychophysical data do not depend on level in contrast to the modulation transfer functions obtained from neural recordings in the inferior colliculus in physiological studies. The results highlight differences between the characteristics of modulation processing obtained from neural data and perception. The discrepancies indicate the need for further investigation into physiological correlates of tuning in modulation processing.
研究了载频水平对调制掩蔽调谐的影响，分别针对噪声和音调载波。使用包络功率谱模型从掩蔽检测阈值估计出调制滤波器带宽，对于噪声载波而言，带宽与水平无关，但对于音调载波，带宽似乎随水平增加而减小。然而，调谐似乎更尖锐，可以通过增加调制灵敏度和调制动态范围来解释，而不是通过提高调制频率选择性来解释。这一解释与以下事实一致：对于每个载波水平，添加一个调整到与检测信号调制相同阈值的高通噪声，消除了水平对调谐的影响。总的来说，与生理研究中从下丘脑中的神经记录获得的调制传递函数相比，从心理物理数据中估计的调制滤波器并不依赖于水平。结果突出了从神经数据和感知中获得的调制处理特征之间的差异。这些差异表明需要进一步研究调制处理中调谐的生理相关性。
Zotero 插件