  Maximum Voiced Frequency (MVF) is used in various speech models as the
spectral boundary separating periodic and aperiodic components during the
production of voiced sounds. Recent studies have shown that its proper
estimation and modeling enhance the quality of statistical parametric speech
synthesizers. Contrastingly, these same methods of MVF estimation have been
reported to degrade the performance of singing voice synthesizers. This paper
proposes a new approach for MVF estimation which exploits both amplitude and
phase spectra. It is shown that phase conveys relevant information about the
harmonicity of the voice signal, and that it can be jointly used with features
derived from the amplitude spectrum. This information is further integrated
into a maximum likelihood criterion which provides a decision about the MVF
estimate. The proposed technique is compared to two state-of-the-art methods,
and shows a superior performance in both objective and subjective evaluations.
Perceptual tests indicate a drastic improvement in high-pitched voices.
