Dither is used to minimize quantization artifacts when reducing the bit depth of an audio signal, for example, from 32-bit float to 16-bit. Quantization artifacts are most apparent when a signal is near the low end of its dynamic range, such as during a quiet passage or a fade-out.

Dither minimizes quantization artifacts by introducing very low-level random noise to a signal, which smooths out the distortion that can result when the signal’s bit depth is reduced.

With dither there is a trade-off between signal-to-noise performance and less-apparent distortion. Proper use of dither lets you get better subjective performance when reducing the bit depth of audio.