MediaStreamAudioSourceNode.MediaStreamAudioSourceNode()

var myAudioSource = new MediaStreamAudioSourceNode(context, options);

// define variables
var audioCtx = new (window.AudioContext || window.webkitAudioContext)();

// getUserMedia block - grab stream 获取音频流
// put it into a  把音频流放入 MediaStreamAudioSourceNode
if (navigator.mediaDevices.getUserMedia) {
   console.log('new getUserMedia supported.');
   navigator.mediaDevices.getUserMedia (
      // constraints: audio and video for this app
      {
         audio: true,
         video: false
     }).then(function(stream) {

       // Create a MediaStreamAudioSourceNode
       var options = {
         mediaStream : stream
       }

       var source = new MediaStreamAudioSourceNode(audioCtx, options);
        source.connect(audioCtx.destination);
        }).catch(function(err) {
         console.log('The following gUM error occured: ' + err);
      });
} else {
   console.log('new getUserMedia not supported on your browser!');
}