In-browser DTMF Detection Demo

Using WebAudio to detect DTMF codes (touch-tone phone keys). Live demo here: https://unframework.github.io/dtmf-detect/

References

• https://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling
• http://dsp.stackexchange.com/questions/15594/how-can-i-reduce-noise-errors-when-detecting-dtmf-with-the-goertzel-algorithm#comment26780_15594
• https://github.com/mmckegg/audio-rms
• https://github.com/antoinet/webaudio/blob/master/dtmf-demod.html (original FFT approach which did not pan out)
• http://jetcityorange.com/dtmf/