The SoundPlug was an add-on device that plugged into the Sorcerer's Parallel Port and provided a jack for hooking up a pair of speakers.  Unlike fancier sound options such as the one made by Arrington Software Service which contained an actual DAC and could produce real 4-voice music, the SoundPlug simply looks for data bits coming off the parallel port.  Most Sorcerer programs used this method for creating sound (generating a square wave), so the SoundPlug is compatible with them.

SoundPlug Manual