A segmental formant vocoder based on linearly varying mixture of Gaussians
نویسندگان
چکیده
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 with time within a segment. A new method of smoothing the power spectrum has been used in order to improve modelling with mixtures of Gaussians. Pitch is estimated using the autocorrelation function, and voicing is detected using the autocorrelation function method and the energy in the spectrum. Optimal segment boundaries are obtained using a dynamic programming procedure based on the power normalised log-likelihood of the segment. Magnitude-only sinusoidal synthesis is then used to synthesise speech from the estimated spectrum. Using multiple codebooks an average bit-rate of 500 bps has been obtained.
منابع مشابه
A formant vocoder based on mixtures of Gaussians
Parham Zolfaghari 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 new low bit-rate formant vocoder. The formant parameters are represented by Gaussian mixture distributions, which are estimated from the discrete Fourier transform (...
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