Audacity is a free audio editor. You can record sounds, play sounds, import and export WAV, AIFF, Ogg Vorbis, and MP3 files, and more.

Use it to edit your sounds using Cut, Copy and Paste (with unlimited Undo), mix tracks together, or apply effects to your recordings. It also has a built-in amplitude envelope editor, a customizable spectrogram mode and a frequency analysis window for audio analysis applications. Built-in effects include Echo, Change Tempo, and Noise Removal, and it also supports VST and LADSPA plug-in effects.

Changes in Audacity 1.3.11 beta :

• Bug fixes for:
* Imports and Exports:
- Freeze importing audio files when Default View Mode set to Pitch (EAC)
- Simultaneous On-Demand imports sorted incorrectly
- WAV or AIFF files imported as noise if Preferences set to copy in the data at 24-bit quality
- WMA exports corrupted if they contained metadata
- Metadata Editor appeared before the Export window when exporting to any format
* Effects:
- Crash or hang using Equalization on longer tracks
- Reverse did not reverse clip boundaries
- Nyquist:
- Excessive memory consumption led to slow processing or crashes
- Values appearing in Nyquist effects text boxes were not always the default or previously entered values
- Errors running Nyquist effects in European locales where comma used as decimal separator
- VST effects remained in Effect menu even when re-scanned and no longer available
- Truncate Silence produced incorrect results if silences spanned a block boundary
* Other bug fixes:
- Spurious "not writable/disk full" errors when saving projects
- Playing, rendering or exporting multiple tracks led to desynchronised playback or loss of audio data
- Crash opening Preferences when no recording and/or playback devices enabled or connected
- Preferences window: OK button did not respond to ENTER when a tab selected in left-hand panel
- Mixer Board solo button handling
- After a period launching correctly, Audacity sometimes did not come up on top at launch
• Changes and improvements:
- Linked audio and label tracks disabled until a future Beta version so they can be bug fixed
- Input volume slider will be disabled if it doesn't have proper control of system slider; use the system slider instead
- Proper support for copying/pasting label-with-audio including label text; new Edit > Paste Text to New Label menu item to paste system clipboard
- Contrast Tool now modeless, more intuitive handling of multiple project windows, various other minor improvements

Changes in Audacity 1.2.6 :

- Fix memory leaks on Windows.
- Correct font size problems.
- Enable missing FLAC support.