selectAudioChannel.js

function selectAudioChannel(type) {
  var splitter = audioCtx.createChannelSplitter(2);
  audioSource.disconnect(); // ?
  switch (type) {
    case 'L':
      audioSource.connect(splitter);
      splitter.connect(audioCtx.destination, 0);
      break;
    case 'R':
      audioSource.connect(splitter);
      splitter.connect(audioCtx.destination, 1);
      break;
    default:
      audioSource.connect(audioCtx.destination);
      break;
  }
}