Frequency shifter

A frequency shifter is a device or module that shifts every frequency in an input audio signal by the same fixed amount in hertz (Hz). A pitch shifter multiplies frequencies by a constant factor, which preserves the harmonic relationships between them. A frequency shifter adds or subtracts a fixed amount instead, which changes the harmonic structure of the sound. The results can sound inharmonic or alien, because the shifts do not follow musical intervals. In sound design, frequency shifters create unusual spectral effects, phasing, and otherworldly sounds. Try adding one to a delay feedback loop.