““As a linguist suggests: " There are messages primarily serving to establish, to prolong, or to discontinue communication, to check whether the channel works (“ Hello, do you hear me?”), to attract the attention of the interlocutor or to confirm his continued attention (“ Are you listening?” or in Shakespearean diction, “Lend me your ears!”— and on the other end of the wire “Um-hum!”).””
