Telephone system with caller identification - uses signal generators producing audio identification logo for acceptance by called subscriber or answering machine

摘要

Each subscriber using the system has a telephone (20,22) connected to a local exchange (2,4); the exchange being interconnected by a trunk line (6). Each exchange has a speech frequency unit (8,10) contg. a DTMF tone combination generator (12,16) and a logo recognition circuit (14,18). The system is esp. useful for the automatic transfer of messages between spoken message recording and transmission services and answering machines. The message is only sent after the recipient has been correctly identified and the proposed call has been accepted at the receiving end.