DSP Restoration Techniques for Audio

The CD revolution of 1984 unleashed a massive campaign of rerelease of vintage analog recordings. To their collective horror, record labels found that many of the original master recordings had deteriorated. Often the only existing copy of a recording was a vinyl pressing. This rush to release beloved music in the new digital form spawned intense interest in digital methods of restoring these old recordings. A number of DSP techniques have been developed to give new life to these recordings. This paper is a survey of some of those methods.