This is a demo for Goertzel.js. It can detect dial-tones(aka DTMF, Touch-tone) through your microphone. This will only work in newer versions of modern browsers such as Google Chrome and Firefox, or any browser that properly supports WebRTC.
To test the demo, use your phone(or play this video) to generate dial-tones. The browser should pick up samples through your microphone and use them to detect the dial-tones. The corresponding digits should appear below.