"Shorten is a fast, low complexity waveform coder (i.e. audio compressor), originally written by Tony Robinson at SoftSound. It can operate in both lossy and lossless modes. Thanks to Michel 'DMX' Bagmeijer for the port of 3.6.0 version to AmigaOS m68k and WarpOS.
Download from: http://amiga.sourceforge.net/