Dither is a small, deliberately added noise applied just before audio is reduced to a lower bit depth — for example when a 24-bit mix is rendered to a 16-bit master. Without it, quantization error correlates with the signal and becomes audible distortion that is worst on fades and quiet passages. Dither randomizes the rounding so the error becomes a steady, benign noise instead, preserving detail below the least significant bit that would otherwise be lost. Noise-shaped dither pushes that noise into frequencies the ear is less sensitive to, lowering its perceived level. The rule of thumb: dither once, at the final bit-depth reduction, never repeatedly.
The book · Volume 4 of 7
Audio for Video: A Complete Guide to Sound in Video Products: From PCM and Codecs to Loudness, Accessibility, and Real-Time Voice Processing
Dither decides whether a 24-bit master turns into a clean 16-bit file or one with gritty distortion on every fade. This volume covers dither in detail alongside sampling, bit depth, dynamic range and the noise floor, so you can pick word lengths and render settings with numbers rather than habit. Written by Nikolay Sapunov, CEO at Fora Soft.
Rendering 16-bit deliverables and hearing grit on quiet fades and dither choices?
Send us a sample of your export chain and we will point out where dither and bit-depth conversion should happen and which settings to lock in. 250+ video products shipped since 2005.
