Neural Processing of Acoustic Signals

Abstract

Like all sensory systems, auditory systems have been shaped by the stimuli that carry meaning for the animals they serve (see Hoy, Chapter 1; Michelsen, Chapter 2; Römer, Chapter 3; Robert and Hoy, Chapter 6; Barth, Chapter 7; Fullard, Chapter 8). It thus comes as no surprise that auditory neurons and neural circuits are specialized to detect and analyze those sounds that carry behaviorally important information. The strong effect of selective pressure is particularly evident among insects, where hearing has evolved independently many times (Fullard and Yack 1993; Hoy, Chapter 1), and often seems to be a “special-purpose” modality that serves restricted and obvious behavioral functions. Because of this close relationship between biological function and auditory neurophysiology, the first section of this chapter focuses on the behavioral functions of sound and on how biologically meaningful information is represented by the physical parameters of acoustic signals. Subsequent sections examine how this information is analyzed by the nervous system.