Audacity (audio editor and recorder)

Audacity is a free, easy-to-use audio editor and recorder for Windows, Mac OS X, GNU/Linux, and other operating systems. You can use Audacity to:

• Record live audio.
• Convert tapes and records into digital recordings or CDs.
• Edit Ogg Vorbis, MP3, and WAV sound files.
• Cut, copy, splice, and mix sounds together.
• Change the speed or pitch of a recording.
• Import and export WAV, AIFF, AU, and Ogg Vorbis files.
• Import MPEG audio (including MP2 and MP3 files) with libmad.
• Export MP3s with the optional LAME MP3 encoder library.
• Create WAV or AIFF files suitable for burning to CD.
• Import and export all file formats supported by libsndfile.
• Open raw (headerless) audio files using the “Import Raw” command.

It supports all common editing operations, plus it will mix tracks and let you apply plug-in effects to any part of a sound. It also has a built-in amplitude envelope editor, a customizable spectrogram mode and a frequency analysis window for audio analysis applications.

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