If the sound has gone out on your 16mm projector ... there's a good chance it's a blown Sound Lamp! BRAND NEW this  BRK  4 volt .75A   Sound Reproducer  lamp (also called an Exciter Lamp)  fits Elmo 16mm Sound Projectors and other makes.  (Check your projector manual for the correct bulb type.) 

These lamps are no longer manufactured.  Limited availability.