Active sound absorber
Patent 5267321 Issued on November 30, 1993. Estimated Expiration Date: 
November 19, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 19, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesNoise reducing resonator apparatus Apparatus for reducing the exhaust noise of internal combustion engines or the like Noise reducing resonators, or so-called silators Loudspeaker with motional feedback Active noise reduction system Dynamic loudspeaker driving apparatus Patent #: 5031221 InventorApplicationNo. 794449 filed on 11/19/1991US Classes:381/72, HEARING PROTECTORS, ELECTRICAL381/71.13, Analog or nonadaptive381/71.6, Adjacent ear381/318, Feedback suppression381/322, Specified casing or housing381/418Armature linked to diaphragmExaminersPrimary: Ng, Jin F.Assistant: Le, Huyen Foreign Patent References
International ClassH04R 025/00AbstractThe Active Sound Absorber of the invention is based on an electroacoustical transceiver defined as a bilateral electroacoustical transducer acting as both a diaphragm actuator and motion sensor, and an associated mutual inductance discriminator, in a electroacoustical positive feedback system. Selected embodiment of such a system is an unvented hearing aid where the Active Sound Absorber combats the occlusion effect. | |
