Pulse dialing is when a phone uses a ticking noise to dial a call. It is an emulation of the rotary method of dialling from older phones.
With pulse dialing, a number of clicks are produced on the phone line depending on what number is pressed. The button ‘3’ will produce 3 clicks, the button ‘9’ will produce 9 clicks, and ‘0’ will produce 10 clicks.
Almost all of today’s phone networks use “tone” dialing (emitting a different sounding beep for each button), however most networks are still compatible with the pulse method.