Wavepad

This audio editing software is a full-featured professional audio and music editor for Windows and Mac. It lets you record and edit music, voice and other audio recordings. When editing audio files, you can cut, copy and paste parts of recordings, and then add effects like echo, amplification and noise reduction. WavePad works as a wav or mp3 editor, but it also supports a number of other file formats including vox, gsm, wma, real audio, au, aif, flac, ogg, and more.

Audio Editor Features
Sound editing functions include cut, copy, paste, delete, insert, silence, auto-trim and more
Audio effects include amplify, normalize, equalizer, envelope, reverb, echo, reverse and many more
Integrated VST plugin support gives professionals access to thousands of additional tools and effects
Supports almost all audio and music file formats including mp3, wav, vox, gsm, wma, au, aif, flac, real audio, ogg, aac, m4a, mid, amr, and many more
Batch processing allows you to apply effects and/or convert thousands of files as a single function
Scrub, search and bookmark audio for precise editing
Create bookmarks and regions to easily find, recall and assemble segments of long audio files
Tools include spectral analysis (FFT), speech synthesis (text-to-speech), and voice changer
Audio restoration features including noise reduction and click pop removal
Supports sample rates from 6 to 96kHz, stereo or mono, 8, 16, 24 or 32 bits
Works directly with MixPad Multi-Track Audio Mixer
Easy to use interface will have you editing in minutes
Typical Audio Editing Applications
Trim sound bites out of longer audio files
Reduce vocals from a music track
Cut together audio for radio broadcasts or podcasts
Save files for your iPod, PSP or other portable devices
Create ringtones from music files or recordings
Record voiceovers for multimedia projects
Restore audio files by removing noise, hissing or hums
Normalize the level of audio files