The inferior division of the inner ear, most prominently the utricle, is considered the primary area of hearing in most fishes. The hearing ability of the channel catfish is enhanced by the presence of the swim bladder. It is the main structure that reverberates the echo from other individuals’ sounds, as well as from sonar devices. The volume of the swim bladder changes if fish move vertically, thus is also considered to be the site of pressure sensitivity. The latency of swim bladder adaptation after a change in pressure affects hearing and other possible swim bladder functions, presumably making audition more difficult. Nevertheless, the presence of the swim bladder and a relatively complex auditory apparatus allows the channel catfish to discern different sounds and tell from which directions sounds have come.