| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem of a conventional telephone apparatus to cancel ambient noise, which needs to mount a microphone for collecting ambient noise and a noise suppression circuit on a telephone side, thereby increasing the cost of a telephone. <P>SOLUTION: A noise suppression circuit and a memory to store installation position information and a telephone state of each telephone is included in a telephone controller (exchange or key telephone main device) side. A telephone not in a call placed near a telephone in a call is extracted; the extracted telephone is required to transmit an ambient noise signal; ambient noise is canceled by subtracting an audio signal received from the extracted telephone as an ambient noise signal component from an audio signal transmitted by the telephone in a call; and a clear audio signal is transmitted to a telephone call destination. <P>COPYRIGHT: (C)2012,JPO&INPIT |
