Abstract: Sound is one of the information carriers often used in animal communication. Sound produced by animals is useful not only in intraspecific communication but also in alarm or aggression. Three basic problems in hearing should be resolved, i.e. frequency selectivity, pattern recognition and sound direction detection. With intracellular' recording and single cell staining techniques, frequency selectivity of prirnary auditory neurons in the bushcricket has been studied.
Each neuron has its characteristic best frequency (BF) and tuning curve in response to sound. The central projections of their axons in the prothoracic ganglion are unilateral, non-transsegme-ntal and of some corresponding relation to their BFs. Neural mechanisms for frequency analysis in species-specific song recognition of the bushcricket are discussed.