connect(unit) {
    var u = unit || p5sound.input;
    this.output.connect(u.input ? u.input : u);
    if (unit && unit._onNewInput) {
      unit._onNewInput(this);
    }
  }
Connect to p5 objects or Web Audio Nodes
@method  connect
@for p5.AudioVoice
@param {Object} unit