docs: function(id) {
        var self = this;
        var sound = self._soundById(id);
  
        if (sound && sound._interval) {
          if (self._webAudio) {
            sound._node.gain.cancelScheduledValues(Howler.ctx.currentTime);
          }
  
          clearInterval(sound._interval);
          sound._interval = null;
          self.volume(sound._fadeTo, id);
          sound._fadeTo = null;
          self._emit('fade', id);
        }
  
        return self;
      }