- (telephony) The effect of sound that is picked up by the telephone's mouthpiece and introduced (at low level) into the earpiece of the same handset, acting as feedback.
sidetone - Computer Definition
In a telephone handset, sending a small amount of your voice signal back into your ear through the handset so that you hear yourself talk. It makes the conversation more comfortable when you hear a little bit of your own speech, because you know the line isn't dead. See hybrid.