PURPOSE: To transmit voice by means of wireless optical communication by converting voice in an acoustic equipment into an optical signal, to irradiate it, receiving the optical signal at a location apart from the acoustic equipment, converting the optical signal into an electric signal and reproducing it into the voice.

CONSTITUTION: A voice electric signal in the acoustic equipment is inputted to a terminal 1, it is amplified in terms of AC, the power coltage is regulated by a transformer 3 to match it to a characteristic of an infrared light emitting diode 4, the voltage is applied to the infrared light emitting diode 4, from which an infrared ray is irradiated. The light is collected by a lens 5 and the result is irradiated. A viewer located at a place apart from a television set, for example, receives the infrared light by using a receiver. The light enters the lens 6, the light is irradiated to an infrared photo transistor 7 and the light is converted into an electric signal. The converted electric signal is amplified by an amplifier 8, the voltage is transformed by a transformer 9, the result is supplied to an earphone 10, where the electric signal is reproduced into sound and listened.