The Swezey Digital Filter

Removing Crackle from Phonograph Recordings

Crackle is probably the most difficult problem to deal with when restoring old phonograph recordings.
Crackle is similar to "pops and clicks" except it is continuous and lies buried within the signal itself.
This makes it almost impossible to separate out.
Decrackling is one of the areas in digital signal processing (DSP) theory that still needs significant research and development.
I am unaware of any general solution to this problem.
To address this I have developed several algorithms which depending on the record can significantly decrackle it.
Below is a brief excerpt from MGM Record 30582-A Harlem Nocturne played by David Rose And His Orchestra.

To hear (or download) the unfiltered "before" version Click Here!
To hear (or download) the filtered "after" version Click Here!
Both excerpts are MPEG mp3 audio files. If you need help playing these files Click Here!

Thank you for your interest in the Swezey Digital Filter Program!

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(c) 2009, Thomas F. Swezey. All rights reserved.