What is DTMF (Dual-Tone Multi-Frequency)?

DTMF (Dual-Tone Multi-Frequency) is the tone signalling produced when you press phone keypad digits, used for menus and for entering card numbers by phone.

Silux Call’s PCI module masks DTMF during card entry so digits never enter recordings — dropping you from PCI SAQ-D to SAQ-A scope.

Also searched as: touch tones, keypad tones, dtmf redaction.

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