Aliasing
Definition
Distortion that occurs when a digital audio system attempts to represent frequencies above the Nyquist limit (half the sample rate). The out-of-range frequencies fold back into the audible spectrum as false, inharmonic tones.
In Simple Terms
A type of digital distortion that creates ugly, unrelated tones in your audio. You'll never hear it if you use standard sample rates and decent plugins, they handle it for you.
In Practice
Recording a signal with energy above 24 kHz into a 48 kHz system produces aliasing artifacts, unrelated distortion tones that appear within the audible range.
Common Confusion
Aliasing is prevented by anti-aliasing filters at AD converters. It also occurs within non-linear digital processing (saturation, distortion), which is why oversampling plugins exist.
Sources & Verification
- Shannon, C. E.. Communication in the Presence of Noise (Nyquist–Shannon sampling theorem)Proceedings of the IRE, 1949
- Pohlmann, K. C.. Principles of Digital Audio (6th ed.)McGraw-Hill, 2011
- Smith, J. O.. Mathematics of the Discrete Fourier Transform with Audio ApplicationsStanford CCRMA
Last verified: 2026-05-05