Patent ID: 7740104

Claim:
A nonvented earplug having a sound hole for coupling said earplug to a user's ear canal, said earplug comprising: a) an enclosure encompassing a volume, said enclosure comprising an earshell having a faceplate facing away from a user when the earplug is worn in a user's ear canal, and an end opposite the faceplate, shaped to form a generally airtight seal when inserted in the ear canal, the earshell having no openings to the volume except for a sound hole at the end which provides an acoustic connection between the volume and the ear canal of the wearer; b) said volume subdivided by at least one bulkhead into a plurality of chambers, c) a plurality of acoustic inertance elements, wherein each one of said plurality of chambers is connected to at least one other of said plurality of chambers by an inertance element of said plurality of acoustic inertance elements passing through a bulkhead, whereby said plurality of chambers and said plurality of inertance elements form a plurality of acoustic resonators, and d) one of said plurality of acoustic resonators is coupled to said sound hole.