Guinea pig's immobility response to sound: Threshold and habituation.

Abstract

Minimum tone levels (.125-32.0 kc.) that produced immobility responses (IRs) in 6 guinea pigs were near the thresholds of audibility and 60-90 db. below those for pinna reflexes. The guinea pig''s audibility curve is near man''s to about 10 kc. but extends to 32 or 50 kc. Durations of IRs to tone initially ranged from 2 sec. to 36 min. and were longer for high than low SPLs; responses ceased in 10-13 trials. Generalization gradients over frequency and intensity showed selective habituation. IRs were evidently influenced by motivational variables and by stimulus novelty.