Speech signals protection via logo watermarking based on the time-frequency analysis

A procedure for logo watermarking of speech signals is proposed. In order to take full advantage of both time and frequency domain, we have used joint time-frequency representation of speech signal, which provides a more comprehensive information compared to each domain individually. Time-frequency based selection of the Discrete Fourier Transform (DFT) coefficients is used for logo embedding. The proposed coefficients selection provides both the imperceptibility and robustness requirements. The binary logo is embedded by using the concept of bit-planes modification. The logo extraction procedure is provided, as well. The robustness of the proposed procedure is tested under various attacks such as compression, noise addition, filtering, re-sampling, requantization, time stretch, pitch scaling, etc.