Linguists and language teachers frequently need to edit or modify sound recordings: they may want to cut just one word out of a long recording, reduce background noise, normalize the volume of several recordings, cut parts of a recording out, or change the format of a recording to mp3 or another format.
Audacity is a free, open-source sound editor that is fairly easy to use and performs all the above functions admirably. Audacity is available for Microsoft Windows, Mac OS X, GNU/Linux, and other operating systems. There are many websites describing how to use Audacity, including this one.
