Perceptually hidden data transmission over audio signals

A data transmission framework is proposed to embed digital data into an audio signal in a perceptually undetectable or almost undetectable way. The resulting signal can be reproduced as is with no loss of acoustic quality; the embedded data can be exactly retrieved at the decoder. The transmission process exploits the perceptual redundancy of the audio signal to conceal the acoustic impact of the embedded data; encoding of side information is used to inform the receiver of the time-varying structure of the masking properties of the audio signal. A sample implementation is described with a throughput of the order of 30 kbit/sec over CD-quality audio.