US Patent 10178457 Audio output assembly for a head-mounted display

A head-mounted display (HMD) includes a housing defining an enclosure having an aperture. A is speaker positioned within the enclosure, the speaker having a back side facing an interior surface of the housing and a front side facing away from the interior surface of the housing, a back volume defined between at least a portion of the housing and the back side of the speaker for enhancing sound generated by the speaker. A sound conduit having an end open to the enclosure and extends outside the housing through the aperture. The sound conduit has another end open toward a rear direction to transmit the sound generated by the speaker.