An answering machine is an electronic device designed to intercept incoming calls from a landline telephone and record messages from the person attempting to contact the phone's owner. An answering machine will pick up a call after a certain number of rings and then play a pre-recorded message to the person calling. There is usually a distinctive beep after the message ends, indicating that the caller can begin recording a message for the owner of the answering machine. The first commercially available answering machines used audio cassettes, usually in pairs, to store a greeting from the owner and to record any incoming messages, although most machines started to use digital storage devices as technology advanced. The difference between an answering machine and voicemail is that the machine needs to be within a certain physical proximity to the location of a telephone or telephone jack to function, while voicemail is usually software provided by a host independent of the owner’s telephone.
The earliest answering machines were analog devices that used audio cassettes for all recording and playback functions. These machines relied on physically rewinding and playing the tapes to provide the greeting for an incoming call and to record messages. The technology worked well but was prone to accidents that could destroy messages or render the machine unusable until someone attended to the issue. Most problems took the form of the cassettes getting caught in the recording mechanism and breaking or jamming the gears that turned the tape.
Advances in computer technology saw the introduction of answering machines that used digital memory to store both the greeting and the messages. This was a much more reliable method of recording messages, although early versions were hindered by having very little storage space, limiting the amount of data that could be stored. When computers became more prevalent, software was developed that would allow a computer to act as an answering machine when the phone line was attached to the modem, although this meant the computer needed to be left on at all times.
In addition to the basic tasks of answering calls and recording messages, answering machines started to integrate more convenient functions as they grew in popularity. Features such as allowing the owner to check messages remotely from any phone, or even providing separate digital mailboxes, started to become more commonplace. Many phones even come with an answering machine built directly into the base. An advanced answering machine can integrate itself with basic telephone services such as caller ID and call waiting to provide more comprehensive management of calls when the owner is away.