docs: function(options) {
    var self = this;
  
    self.sounds = [];
  
    // Setup the options to define this sprite display.
    self._width = options.width;
    self._left = options.left;
    self._spriteMap = options.spriteMap;
    self._sprite = options.sprite;
    self.setupListeners();
  
    // Create our audio sprite definition.
    self.sound = new Howl({
      src: options.src,
      sprite: options.sprite
    });
  
    // Setup a resize event and fire it to setup our sprite overlays.
    window.addEventListener('resize', function() {
      self.resize();
    }, false);
    self.resize();
  
    // Begin the progress step tick.
    requestAnimationFrame(self.step.bind(self));
  }