In this telephone answering device, a new outgoing announcement can be recorded under remote control via the telephone line. To accomplish this, the user calls his own number. During the incoming message record portion of the resultant answering cycle, the user sends a coded signal over the telephone...http://www.google.de/patents/US4306117?utm_source=gb-gplus-sharePatent US4306117 - Remote recording of new outgoing announcement in a telephone answering device
