A vocal tract area ratio estimation from spectral parameter extracted by straight

Approximating vocal tract by a series of acoustical tubes, reflection coefficients between the tubes are essential parameters for vocal tract area estimation. These parameters have been obtained through PARCOR analysis, with some devices to eliminate undesirable effects of fundamental period and radiation between lips. In this paper, vocal tract ratio estimation method is proposed using temporally and spectrally smoothed spectral envelope obtained by STRAIGHT speech analysis and synthesis method. The spectrum is transformed PARCOR coefficients, which are used to estimate the vocal area ratios. As a result, the proposed method can make a stable estimate of vocal tract area ratios in both temporal and spectral.