Dooling, R.J. and Searcy, M. (1979). Detection of amplitude modulated noise by parakeets. J. Acoust. Soc. Am. 66, S34.

The threshold for amplitude modulated broad-band noise was measured in parakeets using avoidance conditioning and a modified method of limits procedure. Amplitude modulation thresholds were measured at ten frequencies between 5 and 2560 Hz. Below 40 Hz, modulation thresholds were constant at about 9% modulation depth. Above 80 Hz, the modulation threshold increased with modulation frequency at the rate of about 4 dB/octave. The 3-dB down point of this function is at approximately 150 Hz. These results are compared with data obtained from human listeners using the same experimental apparatus. [Work supported by NIMH Grant #MH31165.]