Abstract: A muffler device for reducing the noise level of an internal combustion engine as exhaust gases and sound waves produced by the operation of the engine are expelled into the atmosphere is disclosed. The device is placed in the exhaust system, being disposed within the exhaust pipe or pipes as close to the exhaust manifold as possible. The device has a sound chamber for attenuating sound waves entering the chamber by deflection of the sound waves back toward their source and a venturi for drawing exhaust gases through the device and expelling them to the atmosphere.