Resolution in azimuth sound localization in the Mongolian gerbil (Meriones unguiculatus).
Minimum resolvable angles (MRAs) for sound localization in azimuth in the gerbil were determined in a behavioral study using tones, 300-Hz bands of noise centered at frequencies between 500 Hz and 8 kHz and broad-band noise of on average 60 dB SPL overall level. Using the method of constant stimuli, seven gerbils were trained in a two-alternative-forced-choice procedure to indicate if sounds were presented to them from the left or from the right by choosing the left or right arm of a Y-shaped cage. The MRA is the minimum angle between two loudspeaker locations that the gerbils discriminated. Animals were either stimulated from the front (N=4) or from the back (N=3). The MRA for broad-band noise randomly varying in level by +/- 6 dB was 23 degrees and 45 degrees for gerbils stimulated from the front or back, respectively. Generally a gerbil's MRA for tones declined up to 2 kHz reaching 20 degrees and 31 degrees for gerbils stimulated from the front or back, respectively, and the MRA was generally increased above this frequency. Results for narrow-band noise stimuli were similar. Results are discussed with respect to the available interaural cues and physiological mechanisms of sound localization in the gerbil.
Maier
Julia K
JK
Zoophysiology and Behavior Group, Institute for Biology and Environmental Science, Carl von Ossietzky University, Postfach 2503, 26111 Oldenburg, Germany.
Klump
Georg M
GM
D000161:Acoustic Stimulation / Q000379:methods*; D000704:Analysis of Variance; D000818:Animals; D003213:Conditioning, Psychological; D005260:Female; D005849:Gerbillinae / Q000502:physiology*; D008297:Male; D013017:Sound Localization / Q000502:physiology*