An ear piece assembly (10, 100, 200, 300, 500, 600, 700, 800, 900, 1000) designed for a stethoscope or other headpiece, and configured to allow rotation of an ear tip (20, 120, 220, 320, 420, 520, 620) of the assembly about a central axis (relative to the rest of the assembly) and to allow limited off axis movement of the ear tip (relative to the rest of the assembly). In typical embodiments, the ear piece assembly is designed to fit a users ear canal and stay in place during typical use without rotational or off axis movement of the ear tip relative to the ear canal, and to provide substantially more comfort to the user than would a headpiece with a conventional ear tip assembly, particularly for prolonged wearing by the user. Other aspects of the invention are a headpiece (e.g., a stethoscope headpiece) or stethoscope including an embodiment of the earpiece assembly, an ear piece housing body configured for use in an embodiment of the earpiece assembly, and an ear tip configured for use in an embodiment of the earpiece assembly.