get event when i touch objects, "an animal for example"

i try to get animated voice when i touch my object (animal), i try this code, it run correctly when i use a cube object from unity, but when i try this code with 3D object that i downloaded , i dont get the voice. script.

//

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class Sound : MonoBehaviour { public AudioClip[] aClips; public AudioSource MyAudio;

 string Animal;
  

 // Start is called before the first frame update
 void Start()
 {
     MyAudio = GetComponent<AudioSource>();
 }

 // Update is called once per frame
 void Update()
 {
     if((Input.touchCount > 0) && (Input.touches[0].phase == TouchPhase.Began))
     {
         Ray ray = Camera.main.ScreenPointToRay(Input.GetTouch(0).position);
         //Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
         RaycastHit Hit;
         if(Physics.Raycast(ray, out Hit))
         {
             Animal = Hit.transform.name;
             switch (Animal)
             {
                 case "a1":
                     MyAudio.clip = aClips[0];
                     MyAudio.Play();
                     break;
                 case "a2":
                     MyAudio.clip = aClips[1];
                     MyAudio.Play();
                     break;
                 case "a3":
                     MyAudio.clip = aClips[2];
                     MyAudio.Play();
                     break;

                 /*case "Lion":
                     MyAudio.clip = aClips[0];
                     MyAudio.Play();
                     break;*/
                 default:
                     print("0000");
                     break;
             }
         }
     }
 }

}