Last updated: December 2007

Audacity, version 1.2.4b, free. Audacity is a free sound editor but it contains several built-in plug-ins (under Effects) and also supports VST plug-ins for audio cleanup. You can download a fully functional version from:

The download file name is, file size is 3.3 MB.

The User Manual is, file size 456 kB. The manual is a collection of htm files so use your web browser to open index.htm. The whole manual can be read and printed from there.

If you have used any audio editor (Cool Edit, etc.), you will find Audacity easy to use. There are a few differences and that’s what the Manual is for. Under Effects I found Noise Reduction and also Get Noise Profile so I decided to see what I could do with sdemo1.wav.

The first half second of sdemo1 is just lead-in (no music) so I selected it and clicked on Get Noise Profile. Then I selected the whole file (all thirteen seconds) and clicked Noise Removal. The slider that controls how much noise is removed defaults to mid-position so I clicked Preview. The Preview function plays only the first three seconds but it sounded OK so I clicked Remove Noise. Mid-position was too sever and the removal left “artifacts” (distortion) so I clicked Undo to restore the original file, set the slider to 1/4 of full and again clicked Remove Noise. There was just a bit of noise left so I could have tweaked the slider a bit higher and done it again but the resulting file sounded fine so I quit working on it. I’m planning to try a whole restoration project with Audacity and it will be reported on in another Case Study.

The current version is 1.3.2 released in November 2006. I have a copy, it’s still free, but I haven’t taken a look at what new features may have been added.

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