DTMF (Dual-Tone Multi-Frequency) dialing, commercially known as Touch-Tone, is the telecommunication signaling system used to transmit keypad inputs over telephone lines. Introduced by AT&T’s Bell System in 1963, it replaced the slower rotary pulse dialing with audible, machine-readable sound frequencies. Today, it is the universal technology behind navigating automated phone menus (“Press 1 for Sales”), entering banking PINs, and submitting telephone data. How DTMF Works
Every time you press a key on a telephone keypad, the device simultaneously generates two distinct audio frequencies. What is DTMF? and how to configure it on Telnyx
Leave a Reply