All vehicles with an internal combustion engine have a muffler located along the exhaust pipe, which helps to reduce acoustic noise emitted by the engine. Most mufflers are passive devices in which the exhaust gas route is laid through cameras and perforated pipes for filtering the frequency of acoustic vibrations without a significant preventing gas flow. Active sound suppression systems use one or more vibrating panels (essentially columns) given using a microprocessor. The microprocessor monitors the operation of the engine and / or acoustic frequencies, spreading in the exhaust pipe and forms a sound shifted in the phase with the noise created by the engine.
