JPS647896A - One speech level loss setting system for pcm time division digital electronic exchange - Google Patents

Abstract

PURPOSE:To maintain a speech even when the phenomenon such as a speech echo, a sound shaking is generated due to a high speech level by changing the setting of a speech level loss value according to the input of a special code from an extension telephone set. CONSTITUTION:The extension telephone set 10 executes a hooking operation to connect to a register 70 and depresses a code '#' predetermined for lowering the speech level. The '#' code is received by the register 70 and is transferred to a central processing unit 30. The central processing unit 30 analyzes this code and instructs to the processor 42 of a digital only line interface part 40 via a bus 60 so as to apply the speech loss of 2dB. The processor 42 of the digital only line interface part 40 changes the setting of the speech loss at the time of the speech between the extension telephone set 10 and the telephone subscriber of an opposite station after an instruction according to the instruction applied from the central processing unit 30. Thereby, the speech echo can be suppressed.