interactive example

DTMF decoder

Press a key or feed a tone; watch it resolve to a digit.

FIG. 1 — DUAL-TONE DECODERengine: @sonoglyph/dsp · recognizer: plugin-dtmf · 48 kHz

(1) keypad

or feed raw tones (Hz, comma-separated)

(2) spectrum · loudest frame · 0–2 kHz

(3) glyph timeline

Press a key — the decoded digit lands here with its confidence and measured pair.

(1) each key synthesizes its row + column pair through the live pipeline — click, or type it on your keyboard · (2) FFT magnitudes of the loudest frame; the guides are the eight DTMF frequencies · (3) glyphs appear when a tone persists ≥40 ms and then ends. Try the tone input with 697 + 1209 — the exact pair for key 1 — then detune one by 3% and watch the recognizer refuse it.