Object Reference not set to an instance of an object

Hey guys I am trying to play an audio clip as soon as my character passes a position of an instantiated object that later gets destroyed. If anyone could help me out. Here is the code

public class TerrainGenerator : MonoBehaviour {

 public GameObject[] Obstacle;
 List<GameObject> objs = new List<GameObject>();
 List<Vector3> obsPos = new List<Vector3>();
 private int gapHeight = 430;
 private int distanceInt = 0;
 private int spacer = 100;
 private float minSpawn = -160;
 private float maxSpawn = 80;
 private float botEdge = -74;
 private AudioSource audioSource;
 public AudioClip getPointSound;

 // Use this for initialization
 void Start () {

     for (int j = 0; j < 5; j++)
     {
         float randFloat = Random.Range(minSpawn, maxSpawn);
         for (int i = 0; i < Obstacle.Length; i++)
         {
             if (i == 0)
             {
                 var obj = Instantiate(Obstacle[i], new Vector3(CameraController.cameraPos.x + 30 + distanceInt, botEdge + randFloat, 0), Quaternion.identity);
                 obsPos.Add(new Vector3(CameraController.cameraPos.x + 30 + distanceInt, -74 + randFloat, 0));
                 objs.Add(obj);
             }
             else
             {
                 var obj = Instantiate(Obstacle[i], new Vector3(CameraController.cameraPos.x + 30 + distanceInt, botEdge + randFloat + gapHeight, 0), Quaternion.identity);
                 objs.Add(obj);
             }
             
         }
         distanceInt += spacer;
     }
     distanceInt -= spacer;
 }
 
 // Update is called once per frame
 void Update () {
     if (BirdMovement.BirdAlive)
     {
         if (CameraController.cameraPos.x > 1)
         {
             if (CameraController.cameraPos.x % spacer == 0)
             {
                 //Debug.Log("Created Object");
                 float randFloat = Random.Range(minSpawn, maxSpawn);
                 for (int i = 0; i < Obstacle.Length; i++)
                 {
                     if (i == 0)
                     {
                         var obj = Instantiate(Obstacle[i], new Vector3(CameraController.cameraPos.x + 30 + distanceInt, botEdge + randFloat, 0), Quaternion.identity);
                         objs.Add(obj);
                         obsPos.Add(new Vector3(CameraController.cameraPos.x + 30 + distanceInt, -74 + randFloat, 0));
                         //Debug.Log(obj.transform.position);
                     }
                     else
                     {
                         var obj = Instantiate(Obstacle[i], new Vector3(CameraController.cameraPos.x + 30 + distanceInt, botEdge + randFloat + gapHeight, 0), Quaternion.identity);
                         objs.Add(obj);
                     }
                 }

             }
         }

         // Removing gameobjects after the camera has gone past them
         foreach (GameObject go in objs.ToArray())
         {
             if (go.transform.position.x < CameraController.cameraPos.x - 300)
             {
                 Destroy(go);
                 objs.Remove(go);
             }
         }

        
         Vector3 pos = BirdMovement.BirdPosition.transform.position;
         
         foreach(Vector3 obstaclePos in obsPos.ToArray())
         {
             if(pos.x > obstaclePos.x)
             {
                 audioSource.clip = getPointSound;
                 audioSource.Play();
                 BirdMovement.scoreCount++;
                 Debug.Log(BirdMovement.scoreCount);
                 obsPos.Remove(obstaclePos);
                 // Not sure why this line is not working but now is
                 GameObject.Find("Conch").GetComponent<TextMesh>().text = BirdMovement.scoreCount.ToString();
                                 
             }
         }

         
     }       
 }

}