Definition

Noun: A type of modem that converts digital electrical signals from a computer into audible sound tones (like those on a telephone) for transmission over a standard voice telephone line, and converts received sound tones back into electrical signals.

Usage

An acoustic modem is a specific type of data communication device. It is used to connect computers to networks or other computers via the public switched telephone network (PSTN). Its defining characteristic is its use of an acoustic coupler.

Examples

• Noun:
  • The early home computers often used an acoustic modem to connect to bulletin board systems.
  • Before direct electrical connections became standard, travelers would place their telephone handset into the cradle of an acoustic modem to send data.

Advanced Usage

• Historical Context: Acoustic modems were prevalent before telephone lines were commonly fitted with modular jacks (RJ11 connectors). They are now largely obsolete, having been replaced by direct-connect modems and broadband technologies, but are notable in the history of telecommunications and personal computing.
• Functionality: The device typically has two rubber cups where the telephone handset is placed. One cup contains a speaker to transmit tones into the telephone's microphone, and the other contains a microphone to receive tones from the telephone's speaker.

Variants and Related Words

• Modem (n): A more general term for a device that modulates and demodulates signals for transmission over communication lines. An acoustic modem is a subtype.
• Acoustic coupler (n): The physical component or assembly that interfaces with the telephone handset. This term is often used interchangeably with "acoustic modem," though technically it is a key part of one.

Synonyms

• Acoustic coupler: Often used synonymously, though it can refer specifically to the interface mechanism rather than the entire modem unit.

Related Terms (Not Phrasal Verbs or Idioms)

• Direct-connect modem: A later type of modem that connects electrically to the telephone line, bypassing the need for an acoustic coupler. This is the antonymous technology.
• Dial-up: A method of Internet access that uses modems over telephone lines. Early dial-up often utilized acoustic modems.

Noun

1. a modem that converts electrical signals to telephone tones and back again