ABSTRACT
Normal hearing provides depth and space, perspective and separation, effects and atmosphere by 360° spatial hearing. The ear/brain judges direction of sound by the time difference of sound arriving at the ear. This ‘time of arrival’ difference is what must be considered when recording and handling stereo audio signals. Television mono sound originates from a single speaker but television stereo sound attempts to provide an approximation of normal sound experience. Ambisonics or surround sound takes the stereo image further and allows signals to appear all around the listener. For television, ambisonics is commonly reproduced using five loudspeakers, one either side of the screen with a third placed under or over the screen and two further speakers placed behind the viewer. The ambisonic signals can be processed to feed a larger number of speakers. Many television sets in use are not equipped with stereo sound and therefore stereo transmissions must be compatible with mono reception.
