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:
Apr. 14, 1998
Filed:
Dec. 27, 1994
Applicant:
Inventors:
Toshio Yoshida, Tokyo, JP;
Michitaka Sisido, Tokyo, JP;
Assignee:
NEC Corporation, Toyko, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
381169 ; 321 92 ; 321168 ;
Abstract
An arrangement for noise removal according to the present invention includes a microphone and an acoustic high-pass filter positioned in front of the microphone and consisting of the combination of an acoustic resistance, an acoustic compliance and an inertance. According to the invention, the acoustic resistance is composed of nonwoven fabric; the acoustic compliance, of a cavity; and the inertance, of a thin cavity connected to said cavity. This acoustic high-pass filter reduces unpleasant noise which arises from the microphone when a low-frequency high-pressure air stream, such as the speaker's breath, hits the mouthpiece of the telephone.