Patent ID: 8712088

Claim:
An earphone, comprising: an acoustic driver that transduces applied audio signals to acoustic energy; a housing containing the acoustic driver, the housing including a front chamber acoustically coupled to the acoustic driver; an ear interface comprising an outlet structure and a compliant positioning and retaining structure, the outlet structure extending from the housing and dimensioned and arranged to fit inside a user's ear canal entrance when the earphone is worn, providing a passageway for conducting acoustic energy from the acoustic driver to the user's ear canal; and the positioning and retaining structure extending from the housing and configured to apply outward pressure along a substantial length of the antihelix of the user's ear to retain the earphone in the user's outer ear; wherein the positioning and retaining structure has an outer edge and an inner edge, each extending from a base near the housing and meeting at a tip distant from the housing, the outer edge having differing radii of curvature along its length, including a first section at the base having a first radius of curvature and a second section near the tip having a second radius of curvature greater than the first radius of curvature, such that the outer edge is more-sharply curved near the base and less-sharply curved near the tip.