An obsolete piece of equipment that converts acoustic signals from analog to electrical form and back. A common use of an acoustic coupler was to provide an interface between a telephone and an early [..]

cavity of predetermined shape and volume used, for example, for the calibration of earphones or microphones in conjunction with a calibrated microphone adapted to measure the sound pressure developed [..]

1. An interface device for coupling electrical signals by acoustical means--usually into and out of a telephone instrument. 2. A terminal device used to link data terminals and radio sets with the telephone network. Note: The link is achieved through acoustic (sound) signals rather than through direct electrical connection.

A device onto which a telephone handset is placed to connect a computer with a network. The acoustic coupler might also contain a modem, or the modem could be a separate device. Popular in the 1970s, [..]

A special type of modem that converts acoustic energy (sound waves) into electrical energy, allowing a standard telephone handset to be attached to a computer or data terminal for data transmission. 

A hardware

An acoustic coupler is an audio interface device for coupling a computer with audio into or out of a telephone. It may also be a terminal device linking data terminals and radios with telephone networ [..]

<computer hardware, communications> A device used to connect a modem to a telephone line via an ordinary handset. The acoustic coupler converts electrical signals from the modem to sound via a loudspeaker, against which the mouthpiece of a telephone handset is placed. The earpiece is placed against a microphone which converts sound to electri [..]

1. An interface device for coupling electrical signals by acoustical means--usually into and out of a telephone instrument. 2. A terminal device used to link data terminals and radio sets with the telephone network. Note: The link is achieved through acoustic (sound) signals rather than through direct electrical connection.

A type of modem which converts digital signals into sound for transmission through telephone lines, and performs the reverse operation when receiving such signals. Acoustic couplers generally have cups for the telephone handset.