A device to transmit sound to an ear of a user, the ear having an eardrum, a middle ear cavity and a round window membrane, the device comprising: a light source to transmit light energy along the ear canal through the eardrum; a support configured to couple to the round window membrane; and an output transducer assembly comprising at least one photodetector, an output transducer and an anchor structure; wherein the anchor structure is configured to affix the output transducer assembly to a fixed structure of the ear; the at least one photodetector is sized for placement in the middle ear cavity to receive light energy transmitted through the eardrum; and the output transducer comprises a magnet and wherein the output transducer is coupled to the at least one photodetector and is configured to couple to the round window membrane with the support to transmit the sound, wherein the support comprises a non-magnetic material and is configured to retain the magnet of the output transducer in a first configuration and release the magnet of the output transducer from the support in a second configuration; and wherein the at least one photodetector, the support and the transducer are arranged to position the at least one photodetector over the round window niche oriented toward the eardrum to receive light from the eardrum with the transducer between the support and the at least one photodetector. a light source to transmit light energy along the ear canal through the eardrum; a support configured to couple to the round window membrane; and an output transducer assembly comprising at least one photodetector, an output transducer and an anchor structure; wherein the anchor structure is configured to affix the output transducer assembly to a fixed structure of the ear; the at least one photodetector is sized for placement in the middle ear cavity to receive light energy transmitted through the eardrum; and the output transducer comprises a magnet and wherein the output transducer is coupled to the at least one photodetector and is configured to couple to the round window membrane with the support to transmit the sound, wherein the support comprises a non-magnetic material and is configured to retain the magnet of the output transducer in a first configuration and release the magnet of the output transducer from the support in a second configuration; and the anchor structure is configured to affix the output transducer assembly to a fixed structure of the ear; the at least one photodetector is sized for placement in the middle ear cavity to receive light energy transmitted through the eardrum; and the output transducer comprises a magnet and wherein the output transducer is coupled to the at least one photodetector and is configured to couple to the round window membrane with the support to transmit the sound, wherein the support comprises a non-magnetic material and is configured to retain the magnet of the output transducer in a first configuration and release the magnet of the output transducer from the support in a second configuration; and wherein the at least one photodetector, the support and the transducer are arranged to position the at least one photodetector over the round window niche oriented toward the eardrum to receive light from the eardrum with the transducer between the support and the at least one photodetector.