This paper considers aspects of the evolution of the vertebrate auditory system from an `ichthyocentric' perspective. It is argued
that all vertebrate auditory systems are required to do certain basic tasks including acoustic feature discrimination, sound source
localization, frequency analysis, and auditory scene analysis, among others. These sorts of capabilities arose very early in the
evolution of the vertebrates and have been modified by selection in different species. In some cases the same structures have been
involved in detection and analysis throughout the vertebrates, while in other cases the mechanism by which the same type of analysis
takes place may have changed.