Dither

Dithering is the process of adding some very low-level white noise (hiss) to digital audio during bit depth reduction. Why would we want to add noise to our great recording? Consumer devices, such as Hi-Fi, personal MP3 players and car stereos, playback audio at 44.1 kHz and 16 bits. The professional standard for recording audio is either 24 or 32 bits and often at higher sample rates. This means that at the final stage of mastering the bit depth and sample rate of the audio material will have to be reduced to be compatible with consumer devices.