Integrated engine air cleaner and venturi resonator

Abstract From the Canadian patent

An integral air cleaner-noise silencer assembly includes a filter element dividing the assembly into lower and upper parts, the upper part constituting a lid or cover for the filter and including a funnel-like clean air outlet containing a venturi with as small a throat as practical to provide a maximum restriction of noise with a minimum restriction to air flow, the air outlet and venturi being overlaid by a resonator chamber having an annular inlet surrounding and concentric with the venturi diffuser outlet for dampening the acoustical energy of engine sound waves, the venturi diffuser walls also reflecting the waves back toward the engine.