Patent ID: 7085371

Claim:
A push-button signal receiving device for receiving a push-button signal and identifying a dialed number based on the received push-button signal, comprising: amplifying circuit for amplifying the received push-button signal; first and second band-pass filters for passing only signals of low- and high-frequency bands, respectively, included in an output signal of said amplifying circuit; dialed number identifying circuit for detecting frequencies of output signals from said first and second band-pass filters to identify a dialed number, determining validity of the received push-button signal, and outputting the dialed number in accordance with a result of the validity determination; level detecting circuit for detecting signal level of the output signal of said amplifying circuit; and gain control circuit for controlling amplification gain of said amplifying circuit in accordance with the detected signal level, and holding a value of the amplification gain while the received push-button signal is judged valid by said dialed number identifying circuit.