Patent ID: 9728176
Date: 2017-08-08
CPC Classifications: F01N,G10H,G10K,H04R

Claim:
1. A sound generator for an active noise control system for a vehicle with an internal combustion engine, the sound generator comprising: a casing with at least one exhaust gas inlet and at least one exhaust gas outlet different from the at least one exhaust gas inlet; an electro-acoustical transducer configured to produce sound in dependence on an electrical control signal, the electro-acoustical transducer being located directly attached to the casing and the electro-acoustical transducer comprising a moving coil loudspeaker directly attached to the casing, wherein the casing comprises a hole or plural holes at a direct attachment position of the electro-acoustical transducer, the electro-acoustical transducer covering the hole or holes in the casing, wherein sound generated by the electro-acoustical transducer is superimposing sound supplied to the casing together with exhaust gas via the at least one exhaust gas inlet within the casing; and at least one flexible membrane coupled to the casing in an air-tight manner so as to separate the electro-acoustical transducer from the at least one exhaust gas inlet and the at least one exhaust gas outlet, wherein the at least one flexible membrane is provided in addition to the electro-acoustical transducer and the at least one flexible membrane is suitable to prevent corrosive exhaust gas from reaching the electro-acoustical transducer while sound waves generated by the electro-acoustical transducer enter the casing via the flexible membrane.