| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an output acoustic signal of high SN ratio while preventing distortion by acoustic correction when a music piece, etc. is appreciated. <P>SOLUTION: A level detection part 260A<SB>i</SB>(i=L, R) receives an equalizer adjustment signal PES<SB>i</SB>from an equalizer circuit 221A<SB>i</SB>to detect a signal level of an adjustment signal PES<SB>i</SB>to which peak hold is performed by every predetermined period. A detection result is transmitted toward a prestage sound volume specification part 271A<SB>i</SB>as a signal LVD<SB>i</SB>. In the prestage sound volume specification part 271A<SB>i</SB>, a prestage attenuation rate VLF<SB>i</SB>set in a prestage sound volume control circuit 210A<SB>i</SB>is derived based on the signal LVD<SB>i</SB>, and the prestage attenuation rate VLF<SB>i</SB>is transmitted toward a poststage sound volume specification part 272A<SB>i</SB>. The poststage sound volume specification part 272A<SB>i</SB>subtracts the prestage attenuation rate VLF<SB>i</SB>from the total attenuation rate from a control part 252A to derive a poststage attenuation rate set in a poststage sound volume control circuit 222A<SB>i</SB>. <P>COPYRIGHT: (C)2009,JPO&INPIT |
