constructor(type) {
    this.ac = p5sound.audiocontext;
    this.listener = this.ac.listener;
  }
//   * listener is a class that can construct both a Spatial Panner
//   * and a Spatial Listener. The panner is based on the
//   * Web Audio Spatial Panner Node
//   * https://www.w3.org/TR/webaudio/#the-listenernode-interface
//   * This panner is a spatial processing node that allows audio to be positioned
//   * and oriented in 3D space.
//   *
//   * The Listener modifies the properties of the Audio Context Listener.
//   * Both objects types use the same methods. The default is a spatial panner.
//   *
//   * <code>p5.Panner3D</code> - Constructs a Spatial Panner<br/>
//   * <code>p5.Listener3D</code> - Constructs a Spatial Listener<br/>
//   *
//   * @class listener
//   * @constructor
//   * @return {Object} p5.Listener3D Object
//   *
//   * @param {Web Audio Node} listener Web Audio Spatial Panning Node
//   * @param {AudioParam} listener.panningModel "equal power" or "HRTF"
//   * @param {AudioParam} listener.distanceModel "linear", "inverse", or "exponential"
//   * @param {String} [type] [Specify construction of a spatial panner or listener]
//