Digital Audio
Aliasing occurs when a digital system samples an analogue signal at too low a rate, causing high frequencies to be misrepresented as false, lower frequencies in the digital audio.
Aliasing happens when audio is sampled below the Nyquist frequency, which is half the sampling rate. Frequencies above this limit fold back into the audible range as unwanted artefacts or distortion. For example, when sampling at 44.1 kHz, any signal above 22.05 kHz can generate false tones within the audible band.
To prevent aliasing, recording systems use anti-aliasing filters to remove frequencies above the Nyquist limit before conversion. Proper sampling and filtering are critical to maintaining accurate digital representation of the original analogue waveform.
