Earpiece positioning and retaining

A set of positioning and retaining structures of different size for interchangeable use with an earphone, each member of the set comprising an outer edge and an inner edge, each edge extending from a base to be coupled to the earphone and meeting at a tip distant from the base,

• wherein
• the outer edge of each member of the set has 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, and
• the outer edge of each member of the set has a curvature ratio of its first section's radius to its second section's radius, and
• the curvature ratio for each member of the set is within ten percent of the mean of the curvature ratios for all the members of the set.

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 a unitary structure having a body and a positioning and retaining structure, the body being configured to fit within the concha of a user's ear,
• and further including an outlet extending from the body and dimensioned and arranged to fit inside the user's ear canal entrance, the outlet providing a passageway for conducting acoustic energy from the acoustic driver to the user's ear canal;
• the positioning and retaining structure including a compliant member extending from the body 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 member has a curvature generally in a plane, and
• the member is substantially stiffer when force is applied in one rotational direction in the plane than when it is applied in the opposite rotational direction in the plane.

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 a unitary structure having a body and a positioning and retaining structure,
• the body being configured to fit within the concha of a user's ear, and further including an outlet extending from the body and dimensioned and arranged to fit inside the user's ear canal entrance, the outlet providing a passageway for conducting acoustic energy from the acoustic driver to the user's ear canal;
• the positioning and retaining structure including a compliant member extending from the body and configured and 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.