Gain control mechanisms in the auditory pathway.

Belying the apparent ease with which the acoustic world is perceived, the sheer vastness of the range of sounds and sound parameters that must be encoded represents a challenge to traditional models of neural coding in audition. Here, we review recent evidence suggesting that a process of gain control, operating at multiple stages in the auditory pathway, helps maintain coding accuracy to prevailing sound conditions over a wide range of behavioural and sensory contexts. Together, these processes imbue the system with its staggering representational capacity, underpinning everything from the perception of a tiger's near-silent tread to its triumphant roar, demonstrating once more the principle of efficient coding that underlies sensory processing.