Talker speech level control circuit for telephone transmitter by piezoelectric conversion

Abstract From the Canadian patent

A talker speech level control circuit for controlling the level of an electric signal converted from a talker speech, includes an acoustic-electric conversion element for converting an acoustic input signal into an electric signal; a talker speech level detection circuit for detecting whether or not if the speech level of an output signal from the conversion element is within an area representing a need of a speech level control; and a talker speech level adjustment circuit responsive to a signal detected by the talker speech level detection circuit for controlling the electric signal level in accordance with the detected area within which the talker speech level falls.