| abstract |
The invention provides a method and an apparatus for synthetic widening of the bandwidth of voice signals. This is done by providing a narrowband voice signal at a predetermined sampling rate; carrying out analysis filtering on the sampled voice signal using filter coefficients, which are estimated from the sampled voice signal, for envelope widening; carrying out residual signal widening on the analysis-filtered voice signal; and carrying out synthesis filtering on the residual-signal-widened voice signal in order to produce a broader band voice signal. The analysis filtering is carried out using identical filter coefficients to those used for the synthesis filtering. |