| 摘要 |
PROBLEM TO BE SOLVED: To make obtainable a wide band voice having good quality for listening and to reduce the memory capacity and quantity of operation, by dividing a code book for predicting a wide band spectrum envelope into a book for a voiced sound and a book for voiceless sound and making a discriminating method of a voice sound and a voiceless sound different depending on at the time of making a code book or at the time of expanding a band. SOLUTION: This device is provided with a code book 12 for a wide band voiced sound and a code book 14 for a band voiceless sound previously made using voiced sound parameters and voiceless sound parameters extracted from a wide band voiced sound and a voiceless sound, a code book 8 for a narrow band voiced sound and a code book 10 for a narrow band voiceless sound previously made using voiced sound parameters and voiceless sound parameters extracted from a frequency band which is obtained by limiting a frequency band of a wide band voice, for example, a narrow band voice signal of a frequency band 300 Hz-3400 Hz. A narrow band voice signal having a frequency band of, for example 300 Hz-3400 Hz and a sampling frequency of 8 kHz is supplied to an input terminal 1 of a voiced band width expanding device. |
