text: 'use strict';
  
  // Create an instance
  var wavesurfer;
  
  // Init & load
  document.addEventListener('DOMContentLoaded', function () {
      var playButton = document.querySelector('#playBtn'),
          toggleMuteButton = document.querySelector('#toggleMuteBtn'),
          setMuteOnButton = document.querySelector('#setMuteOnBtn'),
          setMuteOffButton = document.querySelector('#setMuteOffBtn');
  
      // Init wavesurfer
      wavesurfer = WaveSurfer.create({
          container     : '#waveform',
          waveColor     : 'black',
          interact      : false,
          cursorWidth   : 0
      });
  
      wavesurfer.load('../media/demo.wav');
  
      wavesurfer.on('ready', function() {
          playButton.onclick = function() {
              wavesurfer.playPause();
          };
  
          toggleMuteButton.onclick = function() {
              wavesurfer.toggleMute();
          }
  
          setMuteOnButton.onclick = function() {
              wavesurfer.setMute(true);
          }
  
          setMuteOffButton.onclick = function() {
              wavesurfer.setMute(false);
          }
      });
  });
  