Coding of communication sounds in the inferior colliculus

Abstract

Many animals, including humans, use species-specific vocalizations to convey biologically relevant information to members of the same species. These communication sounds (referred to as speech sounds in humans and vocalizations in nonhuman animals) are often complex in frequency and time. A fundamental function of the auditory system is to process these complex sounds and impart specific meanings to each sound that are important for communication behaviors. It is unclear how communication sounds are processed and represented in the auditory system, and in particular, it is unclear how these sounds are differentiated from other types of complex sounds. The majority of previous studies have examined processing of communication sounds in the auditory forebrain (Margoliash and Fortune 1992; Ohlemiller et al. 1996; Wang 2000), but the inferior colliculus (IC) likely plays an important role in the neural analysis of communication sounds. We consider the representation of communication sounds in the IC and discuss current evidence for neural specializations in the IC for encoding communication sounds.