Modeling the auditory functions in the primary cortex

Neurons in the primary auditory cortex exhibit distinctive selectivities in responses to various acoustic features. Recent physiological studies suggest three spatial dimensions along which the neural response patterns can be systematically organized: the tuning frequencies of the neurons are logarithmically mapped on the tonotopic axis, and the shapes of the tuning curves, in terms of symmetry and bandwidth, vary gradually along two other spatial dimensions. In this report, it is shown that these variations can be effectively modeled by a complex wavelet transform. With such a tie, one can employ well- established wavelet theories into analyzing and understanding how acoustic signals are processed in the auditory system, and thereby design novel engineering applications that are perceptually oriented.