This "Tarzan" adventure put former Tarzan Mahoney back into the type of villain role in which he started. He plays a power-hungry colonel who threatens Ely's African home with his private army. The ape-man really uses his brain in this one, employing telepathy rather than brawn to subdue a
lion. The silence of the title is the result of hand grenades thrown into a river in the mandatory swim scene. The submerged Ely loses one of his keen senses temporarily because of the blasts. Scriptwriter Steve Shagan (SAVE THE TIGER) is listed as production executive.