You can use
-Wo out.wav
as command line arguments (I assume that's how you use the program) to write a .wav file (which will end up in the current directory if you don't specify one)
Then convert to mp3 with the LAME encoder or any other tool that does this.
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What goes on inside is just too fast and huge and all interconnected for words to do more than barely sketch the outlines of at most one tiny little part of it at any given instant. - D.F.W.