Audacity



Audacity is a popular Open Source tool for creating and editing podcasts; it is freely available to download, install and modify, and is relatively easy to use. You can use Audacity to:
 * Record live audio;
 * Cut, Copy and Paste, Delete, Duplicate, and Split audio files;
 * Change the speed, pitch or volume of a recording;
 * Apply effects to any part of the sound;
 * Align audio segments.