Telephone

Voice mail allows incoming messages to be recorded for later playback when the call is not answered. In advanced forms of voice mail the user may record a message to be sent later in the day.

For residential service voice mail can either be purchased from the telephone company as an exchange-based service or it is available by purchasing an answering machine. This usually contains a regular telephone set along with a recording, playback, and automatic ring detection capability. If an incoming call is answered at any telephone on the line before a pre-set number of rings, the answering machine does nothing. However, after the pre-set number of rings, the answering machine goes off hook and plays a pre-recorded message stating that the owner cannot answer the phone now and inviting the caller to leave a message to be recorded.

The answering machine’s owner is alerted to the presence of a recorded message by a light or audible “beep” and can retrieve the message later. Most answering machines and all exchange-based services also allow the owner to retrieve recorded messages from a remote location by dialling a code after the machine has answered.

Replacement of transoceanic coaxial cables by fibre-optic cables has continued through the 1990s. Advances in integrated-circuit technology and semiconductors have made it possible to design and market telephones that not only produce high-fidelity speech quality, but also offer a host of features such as pre-stored numbers, call forwarding, call waiting, and caller identification. Cellular telephony has grown dramatically, and cellular phones are now offered as standard equipment in many cars.