| 摘要 |
PROBLEM TO BE SOLVED: To improve a clarity of a call voice by expanding a reproduction band of a voice signal restricted to a telephone band.SOLUTION: The present invention relates to a voice band expansion method for improving an acoustic quality of a voice signal output by a telephone device and for outputting the voice signal having a high clarity. A band expansion device includes: higher frequency component generating means for generating a signal component of the band higher in frequency than the band of an input signal based on the input signal; high frequency amplitude estimation means for estimating the amplitude of the original high frequency component according to the spectral shape of the input signal; high frequency amplitude adjustment means for allowing the amplitude of the estimated high frequency component to be reflected on the higher frequency component; and synthesizing means for performing addition to the input signal. |
