DEVICE, METHOD AND PROGRAM FOR ENCODING/DECODING OF SPEECH WITH FUNCTION OF ENCODING SILENT PERIOD

摘要

A voice decoding device smoothes the filter factor intermittently transmitte d similarly to the RMS in decoding a voiceless section and feeds it to a synthesis filter, so that the discontinuous change of the filter factor due to the intermittent transmission can be prevented, and thereby the quality of decoded sound can be improved. To avoid influences of the filter factor and RMS transmitted in a past frame generated by the smoothing operation, the smoothing coefficient is determined so that the smoothing operation is not carried out during a predetermined time or predetermined frames after the decoding enters a voiceless section from a voice section or if the decoded feature parameter fulfills a predetermined condition.