Last modified: November 19, 2020
The first electronic “push button” telephone was introduced on November 18th 1963 by The Bell System, it was designed by Henry Dryfus.
The magic on this devices comes from the dual-tone multi-frequency (DTMF) technology that provides a “touch-tone” feature that will be the world standard in telecommunications to the date. The device uses multi-sound tones on each key that sends an identificable signal to the other end. When a key is pressed it sends a particular tone that is then processed by the switch center office that will decode the sound and determine which key was pressed.» Read more: Push Button day, November 18th »