Temporal summation of pure tones in birds.

Two parakeets and two field sparrows were trained by a method of avoidance conditioning to respond to pure tones. Absolute thresholds were obtained for 10 durations of a 2.86-kHz tone. The temporal integration function for these four birds can best be described by a time constant pi of 230 ms. These data are similar to those reported for a number of other species.