Daniel H. Ashmead
Xuefeng Yang
Robert Wall
Kiara Ebinger
Dept. of Hear. & Speech Sci., Vanderbilt Univ. Med. Ctr., Nashville, TN 37232-8700
This study validates a reaching measure of sound localization for subsequent application to children. Seven adults reached for broadband sound sources while hand position was measured to within 2 mm. Sounds came from 18 regions in frontal reaching space, with the loudspeaker moved away just after stimulus offset. In the ``visual'' condition subjects watched until the sound ended, then closed their eyes and reached. In the ``auditory'' condition subjects were blindfolded. Precision of sound localization was estimated by comparing variability in the visual and auditory conditions: s=[radical s[inf A][sup 2]-s[inf V][sup 2][radical . Estimates were computed for horizontal angle, vertical angle, and distance for each target location. Results agreed reasonably well with conventional measures. For targets straight ahead at ear level, horizontal s=2.6(degrees), vertical s=5.0(degrees), and distance s=9.5%. Systematic variations occurred across target locations. This reaching task is a rapid, naturalistic way of measuring three-dimensional sound localization. [Work supported by DOE and NIH.]