How to add sound effect when collision

Code (CSharp):

1. using UnityEngine;
2.  
3. public class ObjectCollision : MonoBehaviour
4. {
5.    
6.  
7.     void OnCollisionEnter(Collision col)
8.     {
9.         // Recuerde cambiar el nombre de "Enemy" por el nombre de sus game objects con los que colisiona
10.         if (col.gameObject.name == "Peon")
11.         {
12.             GameObject text = GameObject.Find("ScoreText");
13.             GameScore countComponent = text.GetComponent<GameScore>();
14.             countComponent.addPoints(10);
15.             Destroy(col.gameObject);
16.            
17.  
18.         }
19.         else if (col.gameObject.name == "Torre")
20.         {
21.             GameObject text = GameObject.Find("ScoreText");
22.             GameScore countComponent = text.GetComponent<GameScore>();
23.             countComponent.addPoints(15);
24.             Destroy(col.gameObject);
25.         }
26.                 else if (col.gameObject.name == "Caballo")
27.         {
28.             GameObject text = GameObject.Find("ScoreText");
29.             GameScore countComponent = text.GetComponent<GameScore>();
30.             countComponent.addPoints(20);
31.             Destroy(col.gameObject);
32.         }
33.         else if (col.gameObject.name == "Reina")
34.         {
35.             GameObject text = GameObject.Find("ScoreText");
36.             GameScore countComponent = text.GetComponent<GameScore>();
37.             countComponent.addPoints(30);
38.             Destroy(col.gameObject);
39.         }
40.     }
41.  
42. }
43.  

 

Unity has a collection of tutorials about audio here:
https://unity3d.com/learn/tutorials/s/audio