In this paper, a robust and perceptually transparent single-level and multi-level blind audio watermarking scheme using wavelets is proposed. A randomly generated binary sequence is used as a watermark, and wavelet function coding is used to embed the watermark sequence in audio signals. Multi-level watermarking is used to enhance payload capacity and can be used for a different level of security. The robustness of the scheme is evaluated by applying different attacks such as filtering, sampling rate alteration, compression, noise addition, amplitude scaling, and cropping. The simulation results obtained show that the proposed watermarking scheme is resilient to various attacks except cropping. Perceptual transparency of watermark is measured by using Perceptual Evaluation of Audio Quality (PEAQ) basic model of ITU-R (PEAQ ITU-R BS.1387) on Speech Quality Assessing Material (SQAM) given by European Broadcasting Union (EBU). Average Objective Difference Grade (ODG) measured for this method is -0.067 and -0.080 for single-level and multi-level watermarked audio signals, respectively. In the proposed single-level digital audio watermarking scheme, the payload capacity is increased by 19.05% as compared to the single-level Chirp-Based Digital Audio Watermarking (CB-DAWM) scheme.
 COX I. J., MILLER M., BLOOM J. (2002), Digital Watermarking, Academic Press, USA.
 DAUBECHIES I. (1990), The Wavelet Transform, Time Frequency Localization and Signal Analysis, IEEE Transactions on Information Theory, 36, 5, 961-1005.
 FAROOQ O., DATTA S., BLACKLEDGE J. (2008a), Robust Watermarking of Audio with Blind Self Authentication, 7th WSEAS International Conference on Electronics, Hardware, Wireless and Optical communications, Cambridge, UK, February 20-22, 2008.
 FAROOQ O., DATTA S., BLACKLEDGE J. (2008b), Blind Temper Detection in Audio Using Chirp Based Robust Watermarking, WSEAS Transactions on Signal Processing, 4, 4, 190-200.
 PEAQ (1998), International Telecommunication Union(ITU): Method for Objective Measurements of Perceived Audio Quality (PEAQ), ITU-R BS.1387, 1998.
 KABAL P. (2002), An Examination and Interpretation of ITU-R BS.1387: Perceptual Evaluation of Audio Quality (PEAQ), Technical Report, McGill University, Version 2, 2002.
 KIROVSKI D., MALVAR H.S. (2003), Spread Spectrum Watermarking of Audio Signals, IEEE Transactions on Signal Processing, 51, 2, 1020-1033.
 KO B. S., NISHIMURA N., SUZUKI Y. (2005), Time Spread Echo Method for Digital Audio Watermarking, IEEE Transactions on Multimedia, 7, 2, 212-221.
 LANGELAAR G., SETYAWAN I., LAGENDIJK R. (2000), Watermarking Digital Images and Video Data:A State-of Art Overview, IEEE Signal Processing Magazine, 7, 5, 20-46.
 LIE W.N., CHANG L.C. (2006), Robust and High Quality Time-Domain Audio Watermarking Based on Low Frequency Amplitude Modulation, IEEE Transactions on Multimedia, 8, 1, 46-59.
 LILI L., JIANLING H., XIANGZHONG F. (2007), Spread Spectrum Audio Watermark Robust Against Pitch Scale Modification, IEEE International Conference on Multimedia, 1770-1773.
 NEUBAURER C., HERRE J. (1998), Digital Watermarking and Its Influence on Audio Quality, Proc. of AES Convention 1998, San Francisco, CA, 225-233.
 OH H.O., SEOK J.W., HONG J.W., YOUN D.H. (2001), New Echo Embedding Technique for Robust and Imperceptible Audio Watermarking, ICASSP-2001, 1341-1344.
 QUAN X., ZHANG H. (2004), Audio Watermarking Based on a Psychoacoustic Model and Adaptive Wavelet Packets, 7th International Conference on Signal Processing, 3, 1, 2518-2521.
 SHEPPARD N. P., SAFAVI-NAINI, OGUNBONA P. (2001), On Multiple Watermarking, ACM Multimedia Conference-2001, Ottawa, Canada, 3-6.
 VIERU R., TAHBOUB R., CONSTANTINESCU C., LAZARESCU V. (2005), New Results Using Audio Watermarking Based on the Wavelet Transform, International Symposium on Signals, Circuits, and Systems, 2, 1, 441-444.
 WANG X. Y., ZHAO H. (2006), A Novel Synchronization Invariant Audio Watermarking Scheme Based on DWT and DCT,IEEE Transactions on Signal Processing, 54, 12, 4835-4840.
 XIE L., ZHANG J., HE H. (2006), Robust Audio Watermarking Scheme Based on Non-uniform Discrete Fourier Transform, IEEE International Conference on Engineering of Intelligent Systems, 1-5.
 XIONG Y., MING Z.X. (2006), Covert Communication Audio Watermarking Algorithm Based on LSB, International Conference on Communication Technology, ICCT-2006, 1-4.
 XU C., WU J., SUN Q., XIN K. (1999), Applications of Watermarking Technology in Audio Signals, Journal of Audio Engineering Society (AES), 47, 10.