Engineers have sought to eliminate noise since the advent of audio recording just as musicians have sought to harness it. Noise can arise from many sources in the recording process– from the external environment, self-noise from transducers, hum from power sources, and unwanted noises from the musicians themselves. We are interested here in media-specific noise– that is, noises arising directly from the most widely used recording formats. Our focus will be chiefly technical, discussing the physical causes of noise in each media type and looking at their timbral characteristics where possible. This will be followed by a brief look at some of the ways these noises have been used by musicians in their creations. We will begin with analog recording formats–magnetic tape and vinyl records– before moving onto two digital formats– the compact disc and MP3. Not coincidentally, this progression also traces the historical development of these recording formats, and in some cases the noises from a previous generation are inherited by the next, while in other cases they are overcome only to give rise to new sources of noise. We have, by necessity, had to leave out less popular recording formats such as DAT and DVD Audio, although there is much overlap between those formats and the ones discussed here.