Ability of Mice of the Genus Peromyscus to Hear Ultrasonic Sounds

Abstract

Movements of the ears indicate that a Peromyscus has heard a sudden sound. By watching such movements when subjecting these mice to ultrasonic sounds, and by other technics it is found that mice of P. maniculatus strains hear up to 80 kilocycles/ sec. Three individuals of P. nasutus stock, with larger external ears, detected frequencies of 100 kilocycles/sec. Mice subject to audiogenic seizures respond with typical epileptic reactions to ultrasonic tones, although they are less reactive to pure tones than to jangling noises. Old mice generally cannot hear tones as high as can younger ones.