<communications> (DTMF, or "touch-tone") A method used by the telephone system to communicate the keys pressed when dialling. Pressing a key on the phone's keypad generates two simultaneous tones, one for the row and one for the column. These are decoded by the exchange to determine which key was pressed.
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Nearby terms: Dual In-Line Package « dual ported « dual-stack « Dual Tone Multi Frequency » duck typing » DUEL » duff