A new algorithm for translating psycho-acoustic information to the wavelet domain

• Published in: Signal processing Vol. 81; no. 3; pp. 519 - 531
• Main Authors: Rosa Zurera, M., López Ferreras, F., Jarabo Amores, M.P., Maldonado Bascón, S., Ruiz Reyes, N.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2001
• Subjects: Audio coding; Psycho-acoustic; Translation algorithm; Wavelet domain; Wavelet domain; Audio coding; Translation algorithm; Psycho-acoustic
• ISSN: 0165-1684; 1872-7557
• DOI: 10.1016/S0165-1684(00)00230-9

Among the characteristics of a filter bank to be used in subband audio coding, it is desirable that the filter bank and its inverting process maintain a high-frequency selectivity. This design goal is not always met when the audio coder is based on the wavelet transform, making the translation of psycho-acoustic information from the Fourier to the wavelet domain difficult. In this paper, we present a new method for translating the psycho-acoustic information to the wavelet domain, which can be applied to subband audio coders based on the orthonormal wavelet transform, when the subband decomposition approximates the frequency decomposition of sounds in the inner ear. A simple and improved psycho-acoustic model is also described. Both the psycho-acoustic model and the translation algorithm have been included in a wavelet-packet-based audio coder. This uses CD-quality signals and allows transparent coding with binary rates of about 1.5 bits/sample. The inverse relation between the number of vanishing moments of the mother wavelet and the minimum binary rate to ensure transparent coding is shown. A decrease in the number of vanishing moments increases the binary rate slightly, without loss to the subjective quality of the decoded audio signals.