| 摘要 |
PURPOSE:To obtain a device preventing the reduction in talking sound volume between external lines by connecting at least one 2-way direction amplifier to an exchange section of a master equipment, selecting a 2-way amplifier not in use in two-external line conference to amplify the talking sound volume between the external lines. CONSTITUTION:When no 2-way amplifier 21 is in use in the 2-external line conference, the two external lines are connected via the 2-way amplifier 21. In this case, an external line 32 is connected to a key telephone set 21 via a cross point 412, the external line 31 is connected to the key telephone set 21 via a cross point 421, 2-way amplifier 21, cross points 432,412. Thus, the sound volume of thc telephone sets 21 connected to the external line 31 is amplified by the amplifier 21, while the sound volume of the telephone sets 21 connected to the external line 32 is not amplified.
|
