| 摘要 |
PROBLEM TO BE SOLVED: To provide a voice band spreading device and voice band spreading method improving quality of reproduced voice. SOLUTION: The voice band spreading device 1 includes a time-frequency conversion section 11 for calculating the frequency spectrum of a voice signal; a separation section 12 for extracting an envelope amplitude spectrum, a periodical amplitude spectrum and a random amplitude spectrum from the frequency spectrum; an envelope amplitude spectrum band-expanding section 13 for band-expanding of the envelope amplitude spectrum; a periodic amplitude spectrum band-expanding section 14 for band-expanding of the periodical amplitude spectrum; a random amplitude spectrum band-expanding section 15 for band-expanding of the random amplitude spectrum; a wide-band spectrum calculating section 17 for generating a wide band frequency spectrum by synthesizing the band-expanded envelope amplitude spectrum, the band-expanded periodical amplitude spectrum and the band-expanded random amplitude spectrum; and a frequency to time conversion section 18 for generating a band-expanded voice signal, by performing frequency to time conversion on the wide-band frequency spectrum. COPYRIGHT: (C)2011,JPO&INPIT
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