A device that connects a terminal or computer to the handset of a telephone. Acoustic couplers were widely used in the days of analog telephone networks in the 1970-1990s time frame to convert the computer's digital signals to analog sound waves and vice versa. The coupler contained a shaped foam bed that the handset was placed in and may also have contained the modem. See
A/D converter and
modem.
Acoustic Coupler