Audio data hiding is an important branch of information hiding technology. In this paper, a novel digital audio data
hiding scheme, which hides secret message into audio signals, including telephone speech, wideband speech, and
wideband audio, is proposed. The advantage of this scheme is its fully utility of the perceptual masking effect of Human
Audio System (HAS). Before the secret message embedded into the host signal, it is modulated according to the
perceptual masking characteristic of the host signal. Therefore, it is not easily to detect the hiding message in it. This
scheme also uses the cryptographic techniques before hiding message into host audio signal to ensure security.
Moreover, the extraction of the desired message does not need the host audio signal because of the use of the pseudorandom
sequence. Experimental results show that the embedded audio signal is not easily detected and the bit error of the
blind extracted message is small.