Normal vibration frequencies of the vocal ligament

Normal vibration frequencies of the vocal ligament.

The vocal ligament is the tension-bearing element in the vocal folds at high pitches. It has traditionally been treated as a vibrating string, with only length and longitudinal stress governing its normal mode frequencies. Results of this investigation show that, when bending stiffness and variable cross section are included, the lowest normal mode frequency can more than double, depending on t...

Exact Radial Free Vibration Frequencies of Power-Law Graded Spheres

This study concentrates on the free pure radial vibrations of hollow spheres made of hypothetically functionally simple power rule graded materials having identical inhomogeneity indexes for both Young’s modulus and the density in an analytical manner. After offering the exact elements of the free vibration coefficient matrices for free-free, free-fixed, and fixed-fixed restraints, a parametric...

Visualisation of the vocal tract based on estimation of vocal area functions and formant frequencies

A system for visualisation of the vocal-tract shapes during vowel articulation has been designed and developed. The system generates the vocal tract configuration using a new approach based on extracting both the area functions and the formant frequencies form the acoustic speech signal. Using a linear prediction analysis, the vocal tract area functions and the first three formants are first es...

Determination of the vocal-tract shape from measured formant frequencies.

We model the vocal tract as a lossless acoustic tube and consider the relationship between the resonant frequencies and the cross-sectional area function. Empirical results show that if the logarithm of the area function is band limited preserving only 2n Fourier components, the lowest n pole and n zero frequencies of the admittance function measured at the lips uniquely determine the area coef...

Vocal fold vibration patterns and phonatory modes