Acoustical impulse responses of the external ear system are measured in order to investigate human three‐dimensional auditory localization. A sound source of electric spark discharge is presented in nine directions for each of four vertical planes, 1.5 m from the center of the subject’s head. The results show that a human pinna works as a compound sound reflector which produces major reflected components within 350 μs. The relationship between the direction of the sound source and the impulse response is clearly shown by the use of an envelope formation technique and radial ray displays.