html5 audio - Integrating javascript with computer sound input device -

i developing app javascript records audio using html 5 audio context. want develop feature needs whether current active sound device connected microphone or default laptop/computer microphone , adjust settings decreasing volume. there way achieve ?

you can use mediadevices.getusermedia() api method. user prompted permission use audio input device. browser support limited chrome, firefox , opera,see http://caniuse.com/#search=mediarecorder.

navigator.mediadevices.getusermedia({ audio: true }) .then(function (stream) {   // audio stream available here   recorder = new mediarecorder(stream);   // listen dataavailable, gets triggered   // when audio blob available   recorder.addeventlistener('dataavailable', onrecordingready); });  function onrecordingready(e) {   // e.data contains blob represents recording }