Pitch perception in chinchillas (Chinchilla laniger): Stimulus generalization using rippled noise

Rippled noises evoke the perception of pitch in human listeners. Infinitely iterated rippled noise (IIRN) is generated when wideband noise (WBN) is delayed, attenuated, and added to the original WBN through either a positive (+) or a negative (-) feedback loop. The pitch of IIRN[+] is matched to the reciprocal of the delay, whereas the […]

Relative pitch perception in Japanese monkeys (Macaca fuscata)

To investigate whether monkeys perceive relative pitch, the author trained 3 Japanese monkeys (Macaca fuscata) to detect changes from rising to falling contours of 3-tone sequences. Tone sequences were presented serially with transposition, so monkeys were urged to attend to cues other than the absolute frequency of a component tone. Results from probe tests with […]