Audio from scene 1 & 2 continues to play in scene 3 even though it was not added to scene 3.

Hi guys. I used the code below to get the solve the problem of the same song that is playing in scene 1 starting to play from the beginning in scene 2, instead of seamlessly continuing the song when I switch scenes. The song plays in all my menu scenes, regardless of my switching between scenes. But when I switch into the scene that has actual game play, the menu song plays alongside the game play song. The unity console warns that I have 2 audio listeners in my scene, even though I didn't add the audio game object from the menu scenes to the scene that has game play. The script is attached to empty game objects (with an audio listener and an audio source) in the menu scenes, but such a "MenuAudioGameObject" does not exist in the game play scene. Any clue on what I can do?

public class MenuAudio : MonoBehaviour { private static MenuAudio instance;

 void Awake()
 {
     if (instance != null && instance != this)
     {
         Destroy (this.gameObject);
         return;
     } 
     else
         instance = this;

     DontDestroyOnLoad (this.gameObject);
 }

 // Use this for initialization
 void Start () 
 {
     if (!instance.audio.isPlaying)
                     audio.Play ();
 }

 public void TurnMusicOff ()
 {
     if (instance != null)
     {
         Destroy(this.gameObject);
         instance = null;
     }
 }

 void OnApplicationQuit()
 {
     instance = null;
 }

}