Patent ID: 9286882
Filing Date: 2016-03-15
CPC Classification: F01N,G10K,H04R

Claim Text:
1. A controlled noise source for attachment to an exhaust pipe of a vehicle engine, the noise source comprising: a bellows having a first end that couples to the exhaust pipe such that an enclosed internal volume of the bellows is in fluid communication with an interior of the exhaust pipe; and a dynamic driver coupled to an opposite, second end of the bellows; wherein the dynamic driver oscillates the bellows so as to vary the internal volume of the bellows and thereby introduce controlled pressure waves to the interior of the exhaust pipe that counteract a sound produced by the engine; wherein the dynamic driver pushes on the bellows to contract the bellows and push air into the interior of the exhaust pipe, and pulls on the bellows to expand the bellows and pull air out of the interior of the exhaust pipe; and wherein a controller in signal communication with the dynamic driver controls one or more of a frequency, an amount, and a timing with which the dynamic driver contracts and expands the bellows so that the controlled pressure waves are actively generated to counteract the sound produced by the engine.