Answering machine
An answering machine, answerphone, or message machine, also known as telephone messaging machine (or TAM) in the UK and some Commonwealth countries, ansaphone or ansafone (from a trade name), or telephone answering device (TAD), is used for answering telephone calls and recording callers' messages. When a telephone rings a set number of times predetermined by the call's recipient the answering machine will activate and play either a generic announcement or a customized greeting created by the recipient. Unlike voicemail, an answering machine is placed at the user's premises alongside—or incorporated within—the user's landline telephone, and unlike operator messaging, the caller does not talk to a human. As landlines become less important due to the shift to cell phone technology, and as unified communications evolve, the installed base of TADs is shrinking. History Most 20th-century answering machines used magnetic recording, which Valdemar Poulsen invented in 1898. The creation of the first practical automatic answering device for telephones, however, is in dispute. Starting in 1930, Clarence Hickman worked for Bell Laboratories, where he developed methods for magnetic recording and worked on the recognition of speech patterns and electromechanical switching systems. In 1934, he developed a tape-based answering machine which phone company AT&T,