Fredrik L Lindgren

US Patent:

61517178, Nov 28, 2000

Filed:

Jul 20, 1999

Appl. No.:

9/357217

Inventors:

Fredrik Lindgren - Spencer MA
Brian Myers - Indianapolis IN
James Hall - Lincoln RI

Assignee:

Aearo Company - Southbridge MA

International Classification:

A61F 1108

US Classification:

2209

Abstract:

The present invention provides an earmuff device comprising an earmuff cup having at least a window portion which is formed of an optical material which transmits light rays in such a way that the human eye can see through the material to a degree that an earplug or other object inserted within the ear is visually perceivable to the human eye. In other words, the earmuff cup is formed of a transparent material or a translucent material so long as the earplug inserted within the wearer's ear is visually perceivable through the translucent portion of the earmuff cup. Because the earmuff cup is formed of a material that permits an individual, such as a supervisor or hearing conservationist, to perceive whether an earplug is inserted within the wearer's ear, the earmuff device of the present invention is particularly well suited for use in a dual hearing protection environment in which the previous method of compliance monitoring was time consuming and difficult.