Patent ID: 8763752

Claim:
A vehicle air intake duct disposed along an air intake passage of an engine and provided with a noise attenuator which reduces noise transmitting in the duct, the noise attenuator comprising: a pair of circular through holes formed through a duct wall; a pair of wave transmitting/receiving membranes which are stretched so as to close the respective circular through holes, receive a sound wave, and vibrate; a seesaw member which connects between central portions of the paired transmitting/receiving membranes and is pivotally supported with respect to the duct; and an inner limiting member that is opposed to an inner surface of a corresponding one of the wave transmitting/receiving membranes, with a gap being defined therebetween, the inner limiting member extending along the corresponding one of the wave transmitting/receiving membranes and being formed into a grid shape, a reticular shape, a bar shape or a beam shape.