Digital Voice Changer Kit
The construction of this board is the only 'educational' value it offers.  The parts are durable enough for casual work, assuming you have some basic soldering skills.  A novice to such work can easily overheat and ruin some of the parts, so be careful.  The unit itself seems sturdy, with strong connection and switches.  The output is garbage!  You can barely hear anything from the speaker, even at maximum volvume.  It's a toy, and should be considered such when you go to purchase a voice changer module.