The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 17, 1976
Filed:
Sep. 17, 1975
Donald L Johanson, Wayland, MA (US);
United States Surgical Corporation, New York, NY (US);
Abstract
A hearing aid in which the sound reception characteristics are selectable by a user to provide a non-directional or directional reception, as desired. The hearing aid houses a differential transducer having two sound receiving ports communicating with front and rear sound receiving apertures through a network of sound conducting paths. Acoustic switching means are employed to selectably direct sound energy to the transducer through the sound conducting paths, which have equal acoustical impedance in either operating mode, and electric switching means may be associated with the acoustic switching means for adjusting the circuit gain to maintain substantially equal gain for both modes of operation. Frequency characteristics of the hearing aid response in both modes are matched so that switching from one mode to another does not materially alter the quality of sound received from the front of a user.