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