Digital Audio
Dithering adds a small amount of random noise during bit-depth reduction to mask quantisation distortion and preserve low-level detail.
When reducing bit depth, such as converting 24-bit masters to 16-bit for CD, quantisation errors can create distortion in quiet passages. Dithering adds low-level noise to the signal, randomising rounding errors and making them less perceptible.
This process preserves the natural decay of reverb tails and subtle dynamic detail. While dither slightly raises the noise floor, it greatly improves perceived quality, especially when noise shaping is applied to push dither energy into less audible frequency regions.
