### ASA 127th Meeting M.I.T. 1994 June 6-10

## 2pSP34. Multi-channel acoustical modeling of the vocal tract for /l/
production.

**Vladimir M. Barsukov
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*Res. Lab. of Electron., MIT, Cambridge, MA 02139
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Acoustic analysis of the lateral consonant /l/ shows some extra,
unexplained poles and zeros above the second formant. A vocal tract model with
a bifurcation in the acoustic path from the glottis to the lips was analyzed to
explain these acoustic characteristics. The mathematical model consists of a
tube that contains an additional parallel acoustic path or a side branch with
dimensions roughly consistent with the shape of the airways for /l/. A
one-dimensional approximation was used to set up differential equations for
sound pressure P and volume velocity U, appropriate boundary conditions were
applied, and an analytical solution for the problem was found for various
geometrical parameters. The analysis of this solution shows existence of the
extra poles and zeros above the second formant for a reasonable set of
parameters. [Research supported in part by a grant from NIDCD.]