What are the sources of the noises we remove?

摘要

Reissues of analogue recordings, commercial and to a certain extent scientific, perform certain cleaning operations on the raw signal obtained from a sound carrier, such as mechanical recordings, film sound tracks and magnetic recordings. In many cases, background noises are removed based on different statistical properties of noise signals and of the intended signal. However, the models of the noise sources are often simplistic and based more on computational expedience than on characteristic features derived from the mechanism which has generated the noise. In order to improve future endeavours to remove noises without touching components of the intended signal the present paper provides an insight into the mechanisms for noise generation.