Perception of complex sounds at high frequencies

Abstract

Understanding how the auditory system processes frequency and intensity information is crucial to our understanding of overall auditory function. Although great progress has been made in understanding this issue in the case of simple sounds, such as pure tones, considerable uncertainty remains in understanding how the auditory system processes frequency and intensity information in more complex and naturalistic sounds. Moreover, much of our understanding comes from sounds in the low-frequency range, where phase locking to temporal fine structure is available in the auditory nerve. To address these limitations, this dissertation first presents new data on a variety of psychoacoustical tasks measuring frequency and intensity perception not only at low frequencies but also at high frequencies. Next, the psychophysical results are interpreted with the aid of modern computational models of the auditory system, which capture key features of the complex and nonlinear processing that takes place in the auditory periphery and auditory subcortex. Both the behavioral and computational results demonstrate how perception of complex sound features, such as pitch and spectral shape, reflects a delicate combination of both low-level constraints imposed by peripheral encoding of sound and higher-level influences, such as central processing, familiarity, and context.