Electronic telephone terminal having noise suppression function

An electronic telephone terminal having a handset including a transmitter and a receiver, both having substantially linear acoustic-to-electric transduction characteristics, and having a surrounding noise suppression function, comprising:

• a variable attenuator for controlling a gain of a transmission system;
• noise detection means for detecting a surrounding noise level;
• level detection means for detecting an average sound pressure level of a signal output from said noise detection means, and deciding a gain characteristic in response to the detected noise level;
• and
• control means for controlling said variable attenuator in such a manner that when a sound pressure level input to said transmitter exceeds a predetermined threshold value, said gain is fixedly set to a constant value, and when said input sound pressure level is equal to or below said predetermined threshold level, said gain is controlled in response to a change in said surrounding noise level detected by said noise detection means, and further, said control means controls said variable attenuator based on said gain characteristic decided by said level detection means.

A telephone terminal comprising:

• receiver means for receiving a reception signal;
• transmitter means for transmitting a sound signal;
• variable attenuator means for controlling gain in said transmitter means;
• noise detecting means for detecting a surrounding noise level;
• controlling means for controlling said variable attenuator means based on the surrounding noise level detected by said noise detecting means and a sound pressure level of the sound signal.