摘要 |
PCT No. PCT/FR96/00004 Sec. 371 Date Oct. 14, 1997 Sec. 102(e) Date Oct. 14, 1997 PCT Filed Jan. 3, 1996 PCT Pub. No. WO96/21218 PCT Pub. Date Jul. 11, 1996A method comprising the steps of performing a linear prediction analysis of a speech signal digitized in a series of frames divided into sub-frames, in order to determine the parameters of a short-term synthesis filter; carrying out an open loop analysis to detect voiced signal frames and determine, for each voice frame, a degree of signal voicing and a long-term prediction delay search interval containing a number of delays depending on the degree of voicing; carrying out a closed-loop predictive analysis of the speech signal to select, for at least some sub-frames of the voiced frames, a long-term prediction delay contained in the search interval and constituting a long-term synthesis filter parameter; and determining a stochastic excitation for each sub-frame, to minimize a perceptually weighted deviation between the speech signal and the stochastic excitation filtered by the long-term and short-term synthesis filters. |