Abstract: Devices and method for reproducing sound and transmitting a first sound signal and a second sound signal includes a producer having a means for coding the second sound signal, and a means for combining the first sound signal and the coded second sound signal into a composite sound signal that can be reproduced by reproducing means in such a manner that the second sound signal is inaudible to the human ear. A transmitter is provided including a first reproducing means, and a receiver having a means for receiving the composite signal, a means for extracting the coded second sound signal from the composite signal, a decoding means, and a second reproducing means.