CORRELATION BETWEEN INTERAURAL TIME AND INTENSITY DIFFERENCE IN THE SOUND LATERALIZATION

Abstract

It has been said that interaural time and intensity difference play a greatest role in the directional hearing.An apparatus ideally suited in examining the correlation of these two factors which can produce any interaural time differences without changing interaural intensity difference was made.In thisreport, the mechanism of the apparatus and the results obtained were explained.In the complex sounds (music, speech and whitenoise), the just noticeable difference in time was -smaller than in other sounds(continuous and inter rupted pure tones), and it was too large to be estimated in 2, 000cps pure tone.By the centering technique, we examined the interaction between interaural time and intensity -difference and compared time vs, intensity ratios (*t/*i)of 1/2 taveband-noises.It was found that the time vs.intensity ratio was effected by both intensity and frequency of test tone, and that bilaterally lateralized two sound images were recognized as Banister and others reported when the test tone was too loud or inte.raural time difference was too large.Time vs.intensity ratio was the smallest in the 600_??_850cps band-noise(SL.40dB).When test tone was interrupted, the results were different from that of continuous test tone, as follows;1)A sound image located more clearly.2)Even2, 000cps pure tone yields a clear soand image.3)Time vs.intensity ratios were smaller in general.4)Two sound images which lateralized to each earin continuous test tones disapPeared andasingle clear image was heard.