Roll A Ball Sound

So I finished the roll a ball tutorial now im trying to figure out how to play sounds when the ball is rolling, hits the wall with different pitches, and to play a you win! sound when all 12 have been collected. Ive surfed the internet for a while and nothing hasn't been able to work other than coin pick up sounds if anyone doesn't mind explaining how to do this that would be appreciated. Here is the script I have for the player(ball).

Thanks in advanced!

 using UnityEngine;
 using UnityEngine.UI;
 using System.Collections;
 
 public class PlayerController : MonoBehaviour {
 
     public float speed;
     public Text countText;
     public Text winText;
     
     private Rigidbody rb;
     private int count;
     private AudioSource myAudio;
 
     void Start ()
     {
         rb = GetComponent<Rigidbody> ();
         count = 0;
         SetCountText ();
         winText.text = "";
         myAudio = GetComponent<AudioSource> ();
 
     }
 
     void FixedUpdate ()
     {
         float moveHorizontal = Input.GetAxis ("Horizontal");
         float moveVertical = Input.GetAxis ("Vertical");
 
         Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
 
         rb.AddForce (movement * speed);
 
     }
 
         void OnTriggerEnter(Collider other)    
         {
         if (other.gameObject.CompareTag ("Pick Up")) {
             other.gameObject.SetActive (false);
             count = count + 1;
             SetCountText (); 
             myAudio.Play ();
         }
     }        
 
         void SetCountText()
         {
             countText.text = "Count: " + count.ToString ();
             if (count >= 12)
             {
                 winText.text = "You Win!";
             }
         }
     }