Abstract: A self-fitting hearing protection earplug is disclosed that may be easily inserted or withdrawn from an external auditory meatus by first operating an extension mechanism to reduce the diameter of an expansion bulb of the earplug. Contraction of the expansion bulb of the instant invention allows air to pass by during insertion and removal, thus avoiding the uncomfortable “piston” effect of many current earplug designs. In addition to facile insertion and removal, the earplug of the instant invention may be embedded with fine metallic particles, either alone or according to the teaching of U.S. Pat. No. 5,400,296, to make the earplug easily machine detectable. Furthermore, the earplug of the instant invention may be fitted with a speaker/microphone at the distal end to form the basis of a superior two-way communications system for use in high noise environments.

Abstract: A high performance hearing protection or communications earcup and seal is disclosed that takes advantage of the facts that a characteristic acoustic impedance mismatch at a boundary will reflect a large portion of impinging energy rather than absorb it, and the "pumping" action on an elastomeric boundary from cyclic acoustic pressure can be damped by placing damping materials adjacent to that boundary. The preferred embodiment of the hearing protection earcup seal of the instant invention interleaves damping materials between the plurality of concentric ring structures of the instant invention and places thinned edges on individual concentric ring structures to enhance seal conformation with obstacles such as eyeglass temple pieces. An elastomeric semi-annular tensile plate supports the concentric ring structures of the instant invention. Both the earcup and earcup seal of the instant invention are readily manufacturable with conventional tooling.