Dithering

Dithering is the process of adding a small amount of random noise to the digital signal before quantization to reduce the distortion caused by quantization. The added noise spreads the quantization error across a wider range of frequencies, which makes it less audible and more like the original signal.

There are different types of dithering techniques used in digital audio, including triangular, rectangular, and noise-shaped dither. Noise-shaped dither is a more advanced technique that involves shaping the added noise to be more similar to the natural frequency response of human hearing, which can result in even less audible distortion.

Dithering is particularly important in situations where the signal is being downsampled or where the bit depth is being reduced, as these operations can increase the visibility of quantization errors. However, it's important to note that dithering is not necessary in all cases and can sometimes add unwanted noise to the signal. As such, it's important to carefully consider the specific circumstances and requirements of a given audio processing task before deciding whether or not to use dithering.