The African electric fishPollimyrus isidori(Mormyridae) is distinguished among sound‐producing fish by a relatively elaborate repertoire of temporally patterned sounds, produced by males while courting females. Courtship occurs in darkness, and the male's sonic display is evoked by the particular pattern of electrical discharges the female emits. Courtship communication thus involves a bimodal exchange of information mediated by both the auditory and electrosensory systems. Anatomically, these fish exhibit a peripheral specialization for underwater sound‐pressure transduction consisting of the attachment of the sacculus to the wall of a small gas‐filled bladder within the labyrinth. Single‐unit neuro‐physiology has been used to examine responses to sounds propagated through water and to examine the representation of temporally patterned sounds in the central nervous system. ThePollimyrusauditory system is quite sensitive to sounds in the frequency range of those used in communication, with some midbrain neurons having thesholds more than 60 dB below the pressure levels recorded close to sound‐producing males (thresholds of −30 dB or less,re: 1.0 dyn/cm2). The auditory midbrain shows a number of properties expected of a system involved in processing communication and other low‐frequency, temporally patterned sounds. [Work supported by NIH: NRSA DC00020‐02 and CDR P50 DC00293‐06.]