An in-ear device occludes an ear canal of an ear of a user. The in-ear device is configured to be calibrated such that the user perceives audio content as though the in-ear device is not occluding the ear canal. A transducer of the in-ear device presents audio content, and an inner microphone of the in-ear device detects sound pressure data within the ear canal. A controller of the in-ear device determines a blocked sound pressure at the entrance to the ear canal based on sound pressure data from an outer microphone. The controller generates sound filters custom to the user based in part on the detected sound pressure within the ear canal and the blocked sound pressure at the entrance to the ear canal. The controller adjusts audio content using the sound filter, and the transducer presents the adjusted audio content to the user.