Pauline Klaws patented this “appliance for assisting the hearing” in 1902. “It is designed to be worn at lectures, concerts, theaters, and meetings by persons having defective hearing and by the people generally who at such entertainments or meetings, particularly large meetings, are unable or have difficulty in hearing a speaker.”

By 1993 this had evolved into the version below, patented by Mark Tilkens, who found it “particularly useful in hunting of game such as deer, to enhance a person’s ability to hear noises which otherwise may be drowned out by background noise.”