Method and apparatus for canceling tone signal noise generated when using a speakerphone in a digital key telephone apparatus

摘要

A technique for eliminating tone signal noise generated using a speakerphone, in which the communication path of a microphone is interrupted when a key is pressed, and then the communication path of the microphone is linked only after a constant time period after the key has been released, thereby eliminating the noise input through the microphone during usage of the speakerphone.