This test was held in a sound-poof room, and the sources of the sound were all of pure tone. The audiometer receivers were connected to a double audiometer. The examinee had an apparent source of sound and the intensity difference and the time difference varied between both ears. The angular displacement of the apparent source was measured in contrast to the pure tone from a loud speaker connected to a beat frequency oscillator and was audible through spaces between the receivers and the ears. It was ascertained that the value of displacement was proportional to the logarithm of the ratio of intensities. (Stewsat's logarithmic law) Stewart's constant is different according to individuals. The constant does not vary with the increasing frequency. The value of the angular displacement was proportional to the difference of the lengths of two sound-ways. The relation of the angular displacement (θ) with the time difference (T) and intensity difference (I) were as follows; θ=f(1)(I)+f(2)(T) Intensity difference must be of extensively great quantity to remove the apparent source. Time difference is the most important factor in actual localization. Intensity have more influence upon localization in acoustically fatigued Person and in patients with deafness.