| 摘要 |
PROBLEM TO BE SOLVED: To perform band classified sound volume control in a small processing amount or by a small scale circuit. SOLUTION: A sound volume control device 10 includes: a normalization section 11 for normalizing a signal level of an input sound signal (pcm[i]) on a time domain by amplifying it with an amplification rate gain<SB>A</SB>; a modified discrete cosine transformation (MDCT) section 12 for generating a sound signal(mdct<SB>OUT</SB>[f]) on a frequency domain by performing the band division of the input sound signal by applying modified discrete cosine transformation to an output signal (mdct<SB>IN</SB>[i]) of the normalization section 11; a sound volume analysis section 14 for deriving a sound volume control amount (gain<SB>B</SB>[j]/gain<SB>A</SB>) by the division band by analyzing the sound volume of the input sound signal by the division band; and a sound volume control section 15 for amplifying an output sound signal of the MDCT section 12 by the division band by the sound volume control amount. COPYRIGHT: (C)2011,JPO&INPIT |
