It's available for Linux (search for 'sox' in your package manager), Mac OS X and Windows.

pitch shifting, reverb, low pass filtering, flanger, etc). SoX (Sound eXchange) calls itself 'the Swiss Army knife of sound processing programs' and offers, apart from standard audio format and sample rate conversion, a basic set of effects (e.g. Update: also see a follow up blog post about an execution time comparison between SoX, FFmpeg and MPlayer. If you need more/other functionality, look in the man pages or ask your favorite search engine. Note that I only cover the operations I mostly need, like format conversion, sample rate conversion, conversion to mono and trimming/cropping. Having a cheat sheet of how to invoke them with the desired options has proven to be very useful, so here is mine. Because I typically have to do this in batch jobs, I'm mostly dealing with command line tools (on Linux) like Lame, SoX (Sound eXchange), MPlayer and FFmpeg. In my day job, I regularly have to convert/transcode/re-encode audio data from one format to another.

Ffmpeg crop gui