A wireless earbud includes a housing that includes a stem portion and an ear portion. A speaker is positioned within the ear portion together with a first port, the outlet to the ear canal, and a second port formed though a portion of the housing. A microphone and a rechargeable battery is disposed in the stem portion. A pair of electrical contacts is disposed at the distal end of the stem portion with a microphone aperture, inlet, arranged between the pair of contacts. The wireless earbud further comprises an optical concha sensor to sense a user's concha when the ear portion is coupled to the user's ear.