Digital watermark technique based on speech signal

With the fast development of digital signal processing, network and multimedia techniques, the digital watermark technique is applied extensively in the domains of data information identification and data product authentication. The wavelet transform technique can process the data of speech signal etc., the signal can be decomposed into the low frequency and high frequency part of multi-levels, which can be encrypted by the processing of the digital watermark technique, and will attain the encryption or concealment goal of the speech signal. The paper introduces the wavelet transform and its technical application in digital watermarking in speech signals, and the signals of non-encrypted speech before or encrypted speech after are played and compared.