Sound localization (2) ・・・・・Under various conditions

In localizing the source of the sound the following was observed under various conditions in the horizontal plane of the examinee's ears. The range of localization for subjective median, 1. Increased proportionally according to the distance from the source of the sound. 2. Increased by visual stimulus. 3. Increased by auditory fatigue. 4. Decreased when the intense noise was at the background of the source. The sensitivity of localizing sound is separated to two sides, namely the displacement of the apparent source and the range of localization. There has been few reports concerning the latter. Sound localization is produced in the centrum by two auditory nerve excitation. The increased displacement is attributed to unequal nerve excitations, and the increased range of localization to the unclearness of nerve excitation.