Sound Localization in the Horizontal Plane by the House Mouse (Mus musculus)

Abstract

Small mammals such as mice can be expected to have difficulty localizing a sound source, since (a) interaural arrival time differences (ΔT) are small; (b) interaural phase differences (ΔΦ) may be processed only up to about 5 kHz, where phase coding in the auditory nerve rapidly decreases (Rose et al. 1967), so that phase is not helpful for localizing in the high frequency range into which mouse hearing extends (Ehret 1974); (c) interaural intensity differences (ΔI) are nonexistent or small in the lower frequency range. Data on localization of tones and noise do not exist for small mammals (except opossum; Ravizza and Masterton 1972), and we therefore measured sound localization by the house mouse in behavioral tests in order to gain some information about localization acuity and mechanisms.