dentaphone
/dɛnˈteɪfaʊn/Definitions
1. noun
An early device for transmitting telephone messages over short distances using sound waves produced by a bell or other noise-maker.
“The first dentaphone system was used in the late 19th century to send messages across the city.”
2. noun
A device that transmits messages using sound waves.
“The dentaphone was an early attempt to create a wireless communication system.”