in a telephone answering device , artificial intelligence sends an outgoing message to the caller upon receipt of an incoming call . when the caller responds , the artificial intelligence determines whether the caller &# 39 ; s voice is registered with the device , and if so , particular messages are played to the caller . if the caller &# 39 ; s voice is not registered , the caller is notified by the device , and he may receive his specific message by sending a touch tone code from his telephone .