Characteristics of horizontal sound localization of elderly individuals

To investigate the performance of horizontal sound localization of elderly individuals, the authors conducted a test using 19 elderly participants (10 males, 9 females). The stimuli were presented through headphones to their right and left ears with 4 Interaural Level Differences (ILDs) (3, 6, 9, and 12 dB(A)) and 4 Interaural Time Differences (ITDs) (0.2, 0.4, 0.6, and 0.8 ms) besides the same condition to both ears. Pure tones of 0.5, 1.0 and 2.0 kHz, and composite sound of 0.5+2.0 kHz were presented, which lasted one second for each trial. The participants answered ‘Right’ or ‘Left’ after each trial according to their own judgment. The results of the ITD condition showed that in case of the pure tones of 1 kHz, a right-sided inferiority was recognized, which was poorer than the results of the younger participants. Meanwhile, no right/left difference was recognized with the composite sound. Concerning the ILD condition, no right/left asymmetry was shown.