| 摘要 |
PROBLEM TO BE SOLVED: To provide a house information panel whereby a user can hear a received speech signal through a speaker even when a safety device raises an alarm tone in a large tone volume. SOLUTION: A low pass filter 11 whereby a sufficient attenuation amount can be obtained at frequencies of the alarm tone of the safety device and which has filter characteristics for passing through major frequency bands of voice is inserted to a transmission path between a first amplifier 7 and a transmission line loss insertion part 4. Thus, even when the safety device raises the alarm tone, since the low pass filter 11 attenuates the frequency component of the alarm tone included in a transmission signal picked up by a microphone 1, an insertion loss amount control section 6 can easily estimate the speech state to be a speech reception state. As a result, the user can hear the received speech signal through the speaker 2 even in a state that the safety device raises the alarm tone in the large tone volume. COPYRIGHT: (C)2006,JPO&NCIPI
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