Back to results
US 6,324,502 B1Granted
Noisy speech autoregression parameter enhancement method and apparatus
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsPeter Handel, Patrik Sörqvist
Life of this patent
Estimating the term…
Abstract
Noisy speech parameters are enhanced by determining a background noise power spectral density (PSD) estimate, determining noisy speech parameters, determining a noisy speech PSD estimate from the speech parameters, subtracting a background noise PSD estimate from the noisy speech PSD estimate, and estimating enhanced speech parameters from the enhanced speech PSD estimate.
Claims20
A noisy speech parameter enhancement method, comprising the steps of
- receiving background noise samples and noisy speech samples;
- determining a background noise power spectral density estimate at M frequencies, where M is a predetermined positive integer, from a first collection of background noise samples;
- estimating p autoregressive parameters, where p is a predetermined positive integer significantly smaller than M, and a first residual variance from a second collection of noisy speech samples;
- determining a noisy speech power spectral density estimate at said M frequencies from said p autoregressive parameters and said first residual variance;
- determining an enhanced speech power spectral density estimate by subtracting said background noise spectral density estimate multiplied by a predetermined positive factor from said noisy speech power spectral density estimate;
- and
- determining r enhanced autoregressive parameters using an iterative algorithm, where r is a predetermined positive integer, and an enhanced residual variance from said enhanced speech power spectral density estimate using an iterative algorithm.
4 more elements
A noisy speech parameter enhancement apparatus, comprising
- means for receiving background noise samples and noisy speech samples;
- means for determining a background noise power spectral density estimate at M frequencies, where M is a predetermined positive integer, from a first collection of background noise samples;
- means for estimating p autoregressive parameters, where p is a predetermined positive integer significantly smaller the M, and a first residual variance from a second collection of noisy speech samples;
- means for determining a noisy speech power spectral density estimate at said M frequencies from said p autoregressive parameters and said first residual variance;
- means for determining an enhanced speech power spectral density estimate by subtracting said background noise spectral density estimate multiplied by a predetermined factor from said noisy speech power spectral density estimate using an iterative algorithm;
- and
- means for determining r enhanced autoregressive parameters using an iterative algorithm, where r is a predetermined positive integer, and an enhanced residual variance from said enhanced speech power spectral density.
4 more elements
Dependencies are inferred from the claim text.