What Is DTMF?

What Is DTMF?

Dual-Tone Multi-Frequency tones, or DTMF, is a nearly 60-year telecommunications mainstay recognized worldwide. Often referred to by its 1963 Bell System commercial name ‘touch tone’, you interact with DTMF every time you ‘press 1 for Sales’ on a telephone keypad.

DTMF tones are produced when someone presses the numbers of a telephone keypad. Each number key has two tones, one high and one low frequency.

The columns on the keypad are assigned to the high-frequency signals, while the rows are assigned to the low-frequency signals. These in-band signals are combined to create a unique signal pair and then transmitted through voice channels.

DTMF is present across a multitude of services and facilities, from telephone banking and bill payment services to Interactive Voice Response (IVR) menus and conferencing services like Zoom.

Thanks to Spearline

If you are looking for more information on this, read this next: DTMF Masking

Author: Robyn Coppell