Sound Organizer is not compatible with Mac OS X, nor there is a compatible version available. However, many users recommended Audacity as an alternative. Even if it does not have all the functions offered by Sound Organizer, you still have the possibility to control the playback easily.
Audacity works on all Mac versions: http://audacity.sourceforge.net/download/mac
Or, you could run Sound Organizer through Wine Bottler, an emulator for Windows files.