Dummy head recording

In acoustics, the dummy head recording (also known as artificial head, Kunstkopf or Head and Torso Simulator) is a method of recording used to generate binaural recordings. The tracks are then listened to through headphones allowing for the listener to hear from the dummy’s perspective. The dummy head is designed to record multiple sounds at the same time enabling it to be exceptional at recording music as well as in other industries where multiple sound sources are involved. The dummy head is designed to replicate an average-sized human head and depending on the manufacturer may have a nose and mouth too. Each dummy head is equipped with pinnae and ear canals in which small microphones are placed, one in each ear. The leading manufacturers in Dummy Head design are: Brüel & Kjær, Head Acoustics GmBH, Knowles Electronics, and GRAS Sound & Vibration. The human perception of direction is complex: The sound information arriving at the left and right ears causes inter-aural time differences and interaural level differences. These small variations allow the brain and auditory system to calculate the direction and distance of the sound sources from the listener. [See Interaural time difference & Sound localization] With percussive sounds, the impact can be noticed on the skin (usually torso). The strongest and earliest sensory stimulus comes from the skin regions which are aligned perpendicular to the sound source direction. The human head imprints frequency-dependent distortions of phase and amplitude on sounds as they reach the eardrums. The frequency-dependent level differences as well as these distortions vary with the direction of the sound source. This is caused by the geometry and sound-transmitting characteristics of the sinus, throat cavities, eustachian tubes, inner ear, external ears and other tissues of the head and upper body. [See: Head Related Transfer Function, “HRTF”] Conventional music recording is produced for stereo playback which makes use of only Left and Right playback for speakers and headphones.