addImpulse(path, callback, errorCallback) {
    // if loading locally without a server
    if (
      window.location.origin.indexOf('file://') > -1 &&
      window.cordova === 'undefined'
    ) {
      alert(
        'This sketch may require a server to load external files. Please see http://bit.ly/1qcInwS'
      );
    }
    this._loadBuffer(path, callback, errorCallback);
  }
Load and assign a new Impulse Response to the p5.Convolver.
 The impulse is added to the <code>.impulses</code> array. Previous
 impulses can be accessed with the <code>.toggleImpulse(id)</code>
 method.

 @method  addImpulse
 @for p5.Convolver
 @param  {String}   path     path to a sound file
 @param  {Function} callback function (optional)
 @param  {Function} errorCallback function (optional)