Infrared headphones for the hearing impaired
Patent 4633498 Issued on December 30, 1986. Estimated Expiration Date: 
July 9, 2004. 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.
July 9, 2004. 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 ReferencesStage-expanded stereophonic sound reproduction Patent #: 4192969 InventorsApplicationNo. 06/628750 filed on 07/09/1984US Classes:381/23.1, Hearing aid381/26, Stereo sound pickup device (microphone)381/309, Stereo earphone381/311, Wireless or for use in diverse381/74HEADPHONE CIRCUITSExaminersPrimary: Isen, Forester W.International ClassesH04R 5/027 (20060101)H04R 5/033 (20060101) H04R 5/00 (20060101) Foreign Application Priority Data1983-07-11 DEAbstractAn infrared headphone with supplemental microphones to aid the hearing impaired allowing the user to hear the significant sounds from the ambient surroundings. In order to suppress the sound intensity of the user's own voice the invention provides for microphones arranged at a distance from each other on a supporting elbow in such a way that when they are mounted on the head of the user they are symmetrically arranged with respect to a median plane of the user's head and the signals emitted from the microphones are conducted in counter-phase with respect to each other. | |
