In the state of the art, a single frame of DFT transform is commonly used as a basis for building amplitude spectral envelopes.
Multiple Frame Analysis (MFA) has already been suggested for envelope estimation, but often with excessive complexity.
In this paper, two MFA-based methods are presented: one simplifying an existing Least Square (LS) solution, and another one based on a simple linear interpolation.
In the context of singing voice we study sustained segments with vibrato, because these ones are obviously critical for singing voice synthesis. They also provide a convenient context to study, prior to extension of this work in more general contexts.
Numerical and perceptual experiments show clear improvements of the two methods described compared to the state of the art and encourage further studies in this research direction.