发明名称 Automaticaly variable circuit of sound level of received voice signal in telephone
摘要 <p>In an apparatus of adjusting a sound level of a reception voice in a telephone, an audio signal including a transmission voice signal and a peripheral noise is inputted through a microphone. A gain control signal corresponding to a level of the peripheral noise is generated while the transmission voice signal is not present and the gain control signal immediately before input of the transmission voice signal is started is held and outputted while the transmission voice signal is present. A variable gain amplifier amplifies a reception voice signal in accordance with the gain control signal such that a voice corresponding to the reception voice signal is outputted from a speaker with a sound level determined in accordance with the gain control signal. &lt;IMAGE&gt;</p>
申请公布号 EP0717547(A2) 申请公布日期 1996.06.19
申请号 EP19950119291 申请日期 1995.12.07
申请人 NEC CORPORATION 发明人 KURIHARA, KAZUHIRO
分类号 H04M1/60;H04M9/08;(IPC1-7):H04M9/08 主分类号 H04M1/60
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