Two-dimensional vocal tracts with three-dimensional behavior in the numerical generation of vowels

Two-dimensional (2D) numerical simulations of vocal tract acoustics may provide a good balance between the high quality of three-dimensional (3D) finite element approaches and the low computational cost of one-dimensional (1D) techniques. However, 2D models are usually generated by considering the 2...

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Detalhes bibliográficos
Autores: Arnela, Marc, Guasch, Oriol
Tipo de documento: artigo
Data de publicação:2013
País:España
Recursos:Universitat Ramon Llull (URL)
Repositório:DAU Arxiu Digital de la Universitat Ramon Llull
OAI Identifier:oai:dau.url.edu:20.500.14342/5726
Acesso em linha:http://hdl.handle.net/20.500.14342/5726
https://doi.org/10.1121/1.4837221
Access Level:Acceso aberto
Palavra-chave:Speech communication
Vocal tract acoustics
Human voice
Speech analysis
Speech synthesis
Vowel systems
Wave propagation
Telecomunications enigneering
Radiation losses
Organs
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Descrição
Resumo:Two-dimensional (2D) numerical simulations of vocal tract acoustics may provide a good balance between the high quality of three-dimensional (3D) finite element approaches and the low computational cost of one-dimensional (1D) techniques. However, 2D models are usually generated by considering the 2D vocal tract as a midsagittal cut of a 3D version, i.e., using the same radius function, wall impedance, glottal flow, and radiation losses as in 3D, which leads to strong discrepancies in the resulting vocal tract transfer functions. In this work, a four step methodology is proposed to match the behavior of 2D simulations with that of 3D vocal tracts with circular cross-sections. First, the 2D vocal tract profile becomes modified to tune the formant locations. Second, the 2D wall impedance is adjusted to fit the formant bandwidths. Third, the 2D glottal flow gets scaled to recover 3D pressure levels. Fourth and last, the 2D radiation model is tuned to match the 3D model following an optimization process. The procedure is tested for vowels /a/, /i/, and /u/ and the obtained results are compared with those of a full 3D simulation, a conventional 2D approach, and a 1D chain matrix model.