Fig. 9. Auditory sensitivity matches sound production in the frequency domain during social behaviors in the Hawaiian sergeant fish, Abudefduf abdominalis. Audiogram (filled circles) is plotted together with power spectra of A and B pulses of the courtship–female-visit, nest preparation and aggressive (1–2 pulse and >2 pulse) sounds. The greatest energy of all sounds is concentrated from about 100 to 400 Hz, and the region of greatest hearing sensitivity is from 95 to 240 Hz. Threshold data are plotted as means ± s.d. of SPL dB_rms re: 1 µPa (left axis) for all fish pooled (N=24). Power spectra of individual sounds were calculated by 128 point FFT (Hanning window) and are plotted as relative amplitude in dB (right axis).