Influence of tense, modal and lax phonation on the three-dimensional finite element synthesis of vowel [A]

One-dimensional articulatory speech models have long been used to generate synthetic voice. These models assume plane wave propagation within the vocal tract, which holds for frequencies up to ∼ 5 kHz. However, higher order modes also propagate beyond this limit, which may be relevant to produce a more natural voice. Such modes could be especially impor-tant for phonation types with significant high frequency energy (HFE) content. In this work, we study the influence of tense, modal and lax phonation on the synthesis of vowel [A] through 3D finite element modelling (FEM). The three phonation types are reproduced with an LF (Liljencrants-Fant) model controlled by the R d glottal shape parameter. The onset of the higher order modes essentially depends on the vocal tract geometry. Two of them are considered, a realistic vocal tract obtained from MRI and a simplified straight duct with varying circular cross-sections. Long-term average spectra are computed from the FEM synthesised [A] vowels, extracting the overall sound pressure level and the HFE level in the 8 kHz octave band. Results indicate that higher order modes may be perceptually relevant for the tense and modal voice qualities, but not for the lax phonation.