The displacement of a waveform in time. Some electrical components introduce phase shift into a signal. When various frequencies are displaced differently, distortion occurs. Electrical cancellation may occur when two equal signals are out of phase by 1~3()¡. However, this may also be used are a encoding method where the shift is removed on playback (similar to the method in which a Dolby Surround sound track is encoded and played back. (Post Production)