Perception of amplitude fluctuation in the goldfish.

This experiment investigates the extent to which the goldfish’s response to amplitude‐modulated and phase‐manipulated sounds can be predicted by the power of envelope fluctuation. Sixteen common goldfish, Carassius auratus, were classically conditioned to suppress respiration to a 350‐Hz carrier 100% sinusoidally amplitude modulated at 30 Hz. In a subsequently generalization test session, respiratory suppression was measured in the presence of novel signals having either sidebands attenuated or carrier phases shifted up to 90 °. Respiratory suppression declined with both increases in sideband attenuation and increases in phase shift of the carrier frequency. Respiratory responses to both sideband attenuated and phase‐shifted signals declined along a single, monotonic function of envelope power as defined by the normalized fourth moment [W. Hartmann and J. Pumplin, J. Acoust. Soc. Am. 90, 1986–1999 (1991)]. The goldfish’s performance in this experiment is comparable to the performance of human listeners in...