Physiology of Higher Central Auditory Processing and Plasticity

Abstract

Binaural cue processing requires central auditory function as damage to auditory cortex and other cortical regions impairs sound localization. However, the mechanisms through which the cerebral cortex supports spatial perception remain unknown. Sound localization cues are initially extracted by brainstem nuclei. However, localizing a sound within the complex auditory scenes that make up every-day acoustic environments requires integrating information across sound frequencies and localization cues. This chapter reviews evidence that spatial encoding within, and beyond auditory cortex supports sound localization. In particular, this chapter discusses the role of brain regions across the cerebral cortex that may be specialized for extracting and transforming spatial aspects of sounds and extends from sensory to parietal and prefrontal cortices. The chapter considers how the encoding of spatial information changes with attention and how spatial processing fits within the broader context of auditory scene analysis by cortical networks. The importance of neural plasticity in binaural processing is outlined, and how changes in the mapping of localization cues to spatial position allow listeners to adapt to changes in auditory input throughout life and how the brain is able to compensate following hearing loss. The chapter ends by summarizing some of the open questions about central processing of binaural cues and how they may be answered.