Sound Localization in the Horizontal Plane in Patients with Supratentorial Cerebrovascular Disorders.

Abstract

We examined 50 patients with supratentorial cerebrovascular disorders and 59 healthy subjects to learn the capacity of sound localization in the horizontal plane. The experiments were conducted in an anechoic chamber equipped with 12 loudspeakers which were set up in a circle. The subjects heard 6 stimuli per each loudspeaker in a random order, and the capacity of sound localization was evaluated as the number of correctly recognized stimuli per 18 stimuli in each auditory field. Under the anterior field the patients with right and left hemispheric lesions had significantly lower mean score of sound localization than the control (p<0.01). Thirty-eight percent of the patients and 7% of the healthy subjects showed anterior-posterior confusion of sound localization, and the patients with left visuospatial neglect did not exhibit left-right confusion of sound localization. Though we did not find any hemispheric dominance of sound localization, we thought that the brain lesion including an auditory pathway caused the reduction of the capacity of sound localization, especially under the anterior auditory field, and anterior-posterior confusion.