A Multi-Level Representation of f0 using the Continuous Wavelet Transform and the Discrete Cosine Transform

Abstract

We propose a representation of f0 using the Continuous Wavelet Transform (CWT) and the Discrete Cosine Trans-form (DCT). The CWT decomposes the signal into various scales of selected frequencies, while the DCT compactly represents complex contours as a weighted sum of cosine functions. The proposed approach has the advantage of combining signal decomposition and higher-level represen-tations, thus modeling low-frequencies at higher levels and high-frequencies at lower-levels. Objective results indicate that this representation improves f0 prediction over tradi-tional short-term approaches. Subjective results show that improvements are seen over the typical MSD-HMM and are comparable to the recently proposed CWT-HMM, while us-ing less parameters. These results are discussed and future lines of research are proposed. Index Terms — prosody, HMM-based synthesis, f0 mod-eling, continuous wavelet transform, discrete cosine trans-form 1