Stochastic volatility models for speech signals
摘要
The paper studies a new modeling methodology in the short-time Fourier transform domain for speech signals. A robust speech enhancement technique is achieved by using an improved minima-controlled recursive averaging noise estimating technique and an optimally modified log-spectral amplitude estimator, where the spectral variance is estimated based on a stochastic volatility model. The suggested method based on the stochastic volatility model takes into account the heavy-tailed distribution of the short-time Fourier transform expansion coefficients and provides a plausible model to estimate their variances. The speech variances modeled are then estimated using the Bayesian method via the Markov chain Monte Carlo techniques. A comparison to the existing generalized autoregressive conditionally heteroscedastic modeling method is also carried out using different objective quality measures.