An electronic device that changes the phase of an incoming signal. Phase shifters are in the family of time-based effects commonly used on instruments and voices in music production. Phase shifting works by taking the input signal and adding a very small amount of delay to it, and then mixing it back with the original (non-delayed) signal so that certain frequencies of the audio are in or out of phase with each other. The time delay is modulated so the delay amount changes with time. As the delay time changes, different frequencies of the audio waveform will move in and out of phase with each other in the mix of delayed and non-delayed signal. This creates the characteristic sweeping sound of phase shifting processors. The speed and depth (range) of the frequency sweep is usually adjustable. In some phase shifters, various amounts of feedback can be applied to the delayed signal to give a more resonant quality. Additionally, some processors give you more control over the delay amounts, filtering, and other parameters. Phase shifters are often called Phasers for short.