| 摘要 |
PROBLEM TO BE SOLVED: To provide a loudspeaking speech unit realizing a pleasant speech without giving a sense of discomfort to users. SOLUTION: A speaker amplifier 7 monitors a receiver side background noise power estimate value Pn(R) obtained by a second voice interval detection section 12, sets its gain G3 to an initial value G3<SB>0</SB>when the receiver side background noise power estimate value Pn(R) is a threshold value Xc or below, and the speaker amplifier 7 decreases the gain G3 to a value G3<SB>1</SB>smaller than the initial value G3<SB>0</SB>when the receiver side background noise power estimate value Pn(R) exceeds the threshold value Xc. That is, when the gain G3 of the speaker amplifier 7 is fixed to a prescribed value, in the case that surrounding noise of a received signal is high, the sound volume of the noise heard from a speaker 2 is greater than required to sometimes provide a sense of discomfort to the users. Since the gain G3 of the speaker amplifier 7 is decreased when the background noise included in the received signal is greater, the noise volume of unpleasant noise heard from the speaker 2 is decreased so as to realize a pleasant speech not providing a sense of discomfort to the users. COPYRIGHT: (C)2005,JPO&NCIPI |
