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. 10, 1984
Filed:
Apr. 19, 1982
Applicant:
Inventor:
Clayton H Allen, Cambridge, MA (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
181129 ; 181135 ; 128152 ; 1791 / ; 1791 / ; 1791 / ;
Abstract
In an ear muff intended for protection against excessive noise exposure, the passive means according to this invention automatically and continuously varies the amount of reduction provided for the sound arriving at the ear of the wearer; it retains substantially unaltered the performance of the ear muff for high sound levels, but effects a prescribed lesser value of sound reduction at low sound levels and maintains coherent phase relations between the sound waves arriving at the two ears as needed for reception of directional information.