A Study of Horizontal Sound Localization Ability in Normal Koreans

Kwon, Kyoungsoon; Park, Moonsoe; Lee, Junghak

ORIGINAL ARTICLE

Commun Sci Disord. 2001;5(2): 1-14.

Kyoungsoon Kwon^` , Moonsoe Park^` , and Junghak Lee^`

권경순(Kyoungsoon Kwon)| 박문서(Moonsoe Park)| 이정학(Junghak Lee)

ABSTRACT

Sound localization ability is a complex phenomenon resulting from the interaction between the two ear s . Sound localization is possible because of the relative intensity of sound and it s time of arrival at two ear s. T he greatest single contributor s for localizing sound are interaural time disparity in the low frequency (below 1500 Hz) and intensity differences in the high ferquency (above 2000 Hz). T he effect s of the stimulus type, gen - der , age, and direction were ex amined. T his reserch was performed in a nonreberverant room with 49 normal korean subject s aging between 10 to 50. Laudspeaker s which presented the stimuli are located at azimuth angles in 45°increment s around the head. Speech noise, 1/ 3 octave narrow band noise centered at 500 Hz and 4000 Hz, and pure tone 500 Hz and 4000 Hz were used as stimuli. T he result s showed that speech noise was the best stimulu s for localizing sound. Directional discrimination score was very poor in pure tone 4000 Hz group. T here were no significant differences in directional discrimination range among ages and gender s. Front - back of azimuth angle in direction didn t show any differences, but left discrimination was relatively better than right in all stimulus type ex cept NBN 500 Hz. Conclusively, speech noise was the most reliable for sound localization and the low frequency was more reliable than the high frequency for the directional discrimination when u sing a similar stimulus type. T he result s seems to be valuable in evaluation of hearing aid properties and aural rehabilitation.