Balaguer-Ballester Emili, Denham Susan L, Meddis Ray
Centre for Theoretical and Computational Neuroscience, University of Plymouth, Devon PL4 8AA, United Kingdom.
J Acoust Soc Am. 2008 Oct;124(4):2186-95. doi: 10.1121/1.2967829.
Autocorrelation algorithms, in combination with computational models of the auditory periphery, have been successfully used to predict the pitch of a wide range of complex stimuli. However, new stimuli are frequently offered as counterexamples to the viability of this approach. This study addresses the issue of whether in the light of these challenges the predictive power of autocorrelation can be preserved by changes to the peripheral model and the computational algorithm. An existing model is extended by the addition of a low-pass filter of the summary integration of the individual within-channel autocorrelations. Other recent developments are also incorporated, including nonlinear processing on the basilar membrane and the use of integration time constants that are proportional to the autocorrelation lags. The modified and extended model predicts with reasonable success the pitches of a range of stimuli that have proved problematic for earlier implementations of the autocorrelation principle. The evaluation stimuli include short tone sequences, click trains consisting of alternating interclick intervals, click trains consisting of mixtures of regular and irregular intervals, shuffled click trains, and transposed tones.
自相关算法与听觉外周的计算模型相结合，已成功用于预测各种复杂刺激的音高。然而，新的刺激常常被作为这种方法可行性的反例提出。本研究探讨了在面对这些挑战的情况下，通过对外周模型和计算算法进行修改，自相关的预测能力是否能够得以保留。通过添加一个对各个通道内自相关的汇总积分进行低通滤波的环节，对现有的模型进行了扩展。同时也纳入了其他近期的进展，包括基底膜上的非线性处理以及使用与自相关滞后成正比的积分时间常数。经过修改和扩展的模型相当成功地预测了一系列对自相关原理早期实现方式来说存在问题的刺激的音高。评估刺激包括短音序列、由交替的点击间隔组成的点击序列、由规则和不规则间隔混合组成的点击序列、混洗的点击序列以及移调的音调。
