摘要 |
A speech decoder (201) is arranged and constructed to receive a plurality of speech parameters and decode the plurality of speech parameters into at least one fragment of decoded speech. A noise generator (205) is arranged and constructed to output a noise signal. Determining means (203) provide a decision as to whether the plurality of speech parameters represents unvoiced speech. A switch (209), operating together with the speech decoder, the noise generator, and the means for determining, is arranged and constructed to output the noise signal when the plurality of speech parameters represents unvoiced speech. A noise source (2051) e.g. a pseudo-random sequence generator applies a Gaussian noise signal to an LPC filter (2053) which spectrally shapes the noise signal with an estimate of the original speech spectrum envelope as provided by the LPC parameters provided by speech decoder (201). A filter (2055) adjusts the output energy of the noise signal to match the original decoded speech. |