title: Localization of tones and noise in the horizontal plane by unrestrained house mice (Mus musculus).
abstract: House mice (Mus musculus, outbred strain NMRI) were trained to locate loudspeakers at the margin of a wire-mesh covered circular platform. Sound signals were tone bursts of 1, 15, 50 and 80 kHz and noise bursts (bandwidth 15-80 kHz). Localization acuity as represented by orientation angles (alpha) toward the speaker was determined at 5 radial distances from the centre of the platform. If the animals could localize under closed-loop conditions (with repetitive stimulation), the distributions of (alpha) showed a significant peak at the speaker position (0 degrees) and mean orientation angles (alpha) for the different stimuli all varied around 0 degrees. Distributions of (alpha) from open-loop tests were not peaked, i.e. mice did not localize the sound source. We calculated the median angle (beta) of the distributions of orientated runs and used (beta) as a measure for the accuracy of localization. Smallest values of beta were 12 degrees for 1 kHz, 15 degrees for 15 kHz, 9.5 degrees for 50 kHz, 8.5 degrees for 80 kHz tone bursts and 7 degrees for the noise bursts. The results are discussed in relation to possible localization mechanisms in mice.
mesh_terms: D000818:Animals; D001307:Auditory Perception; D005260:Female; D051379:Mice; D013017:Sound Localization; D014465:Ultrasonics