US Patent 8396239 Optical electro-mechanical hearing devices with combined power and signal architectures

An audio signal transmission device includes a first light source and a second light source configured to emit a first wavelength of light and a second wavelength of light, respectively. The first detector and the second detector are configured to receive the first wavelength of light and the second wavelength of light, respectively. A transducer electrically coupled to the detectors is configured to vibrate at least one of an eardrum or ossicle in response to the first wavelength of light and the second wavelength of light. The first detector and second detector can be coupled to the transducer with opposite polarity, such that the transducer is configured to move with a first movement in response to the first wavelength and move with a second movement in response to the second wavelength, in which the second movement opposes the first movement.