Abstract: Deviation in localization of a sound source and differential threshold of sound source position were studied on 43 and 60 subjects,respectively.The mean horizontal deviation in sound source localization was found to be 3.1°,and the mean vertical deviation 4.7°.When the two sound sources to be differentiated were situated near the midplane in front of the subject,with the distance between the sound source and the subject kept at 1.15 m,the mean normal differential threshold of sound source position was found to be 3.5°.As measured in the experiments with binaural presentation of sound,the mean differential threshold of sound source position in terms of binaural intensity difference was 0.70 db,and that in terms of binaural phase difference-28.5 μsec.The horizontal deviation in sound source localization and the differential thresholds obtained with different experimental methods were compared,and their correlation discussed.