A study was conducted to investigate whether spontaneous head movements occurred during natural sound localization. All experiments were performed in an anechoic chamber with the light turned on. The stimulus was a narrow-band noise whose frequency range varied from 150 Hz to 500 Hz without any localization cues for front-back discrimination. The binaural sound pressure level of stimulus was 65 dB measured by using a KEMAR dummy head and an A-weighting filter. The stimulus was radiated to a subject from one of the filled six loudspeakers without any outward difference in appearance between the filled and open loudspeakers. The subjects heard and responded to only one stimulus in every experiment, which was radiated from one of the six filled loudspeakers to investigate the spontaneous head movements during natural sound localization without any training or learning. The head movements of the subjects were recorded and analyzed in three dimensions by motion capture.