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. 26, 2003
Filed:
Jan. 11, 1999
Remo Leber, Bubikon, CH;
Arthur Schaub, Wolfhausen, CH;
Bernafon AG, Bern, CH;
Abstract
A circuit for adaptive suppression of acoustic feedback forms part of a digital hearing aid, comprising a microphone ( ), subtracter ( ), hearing correcting means ( ), receiver ( ), delay element ( ), filter ( ), updating unit ( ), lattice decorrelators ( ) and control unit ( ). The transmission path is modeled with the feedback characteristic ( ) and an adder ( ). First decorrelator ( ) decorrelates the echo-compensated input signal (en) and second decorrelator ( ) decorrelates the delayed output signal (x ) by using coefficients (k ) from first decorrelator ( ). The coefficients (k ) of the two filters ( ) are calculated by adaptive decorrelation of the echo-compensated input signal (e ). This permit maximum convergence rates for minimum distortions. Updating of the filter coefficients mainly takes place where the greatest amplifications occur in the hearing correcting means ( ). The fed-back signal components are continuously removed from the input signal.