A formant vocoder based on mixtures of Gaussians

A segmental formant vocoder based on linearly varying mixture of Gaussians

MIXTURE OF GAUSSIANS Parham Zolfaghari and Tony Robinson Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UK. Tel: [+44] 1223 332754 Fax: [+44] 1223 332662 email : psz1000,[email protected] ABSTRACT This paper describes a low bit-rate segmental formant vocoder. The formants are estimated using mixture of Gaussians whose means are constrained to vary linearly w...

Formant analysis using mixtures of Gaussians

This paper describes a new formant analysis technique whereby the formant parameters are represented in the form of Gaussian mixture distributions. These are estimated from the Discrete Fourier Transform (DFT) magnitude spectrum of the speech signal. The parameters obtained are the means, variances and the masses of the density functions, which are used to calculate centre frequencies, bandwidt...

Application of speaker modification techniques to phonetic vocoding

The goal of the work described in this paper is to develop a very low bit rate vocoding scheme. The vocoder is a typical LPC vocoder, whose parameters are post-processed on a phone-byphone basis, resulting in a variable bit rate segment vocoder. Given the well known speaker recognizability problems presented by vocoders at such low bit rates, we have attempted to integrate a speaker modificatio...

Real Time Pitch Shifting with Formant Structure Preservation Using the Phase Vocoder

Pitch shifting in speech is presented based on the use of the phase vocoder in combination with spectral whitening and envelope reconstruction, applied respectively before and after the transformation. A band preservation technique is introduced to contain quality degradation when downscaling the pitch. The transposition ratio is fixed in advance by selecting analysis and synthesis window sizes...

Comparative formant and channel vocoder performance