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:
May. 31, 1994
Filed:
Oct. 30, 1991
Applicant:
Inventor:
Francois Callias, Neuchatel, CH;
Assignee:
Ascom Audiosys AG, Flamatt, CH;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
381 684 ; 381 682 ; 381106 ; 330251 ;
Abstract
In a hearing aid having a switched amplifier, an amplifier circuit is provided so that the pulse amplitude of the switched output signal is adjusted as a function of the envelope of the audio signal to be amplified. A controllable amplifier is switched in series ahead of the switched amplifier, whereby its control by the audio signal to be amplified proceeds in such a manner that the product of the amplifications of the two amplifiers remains constant for all audio signal levels.