Augmented Reality sound input

Hello. I am trying to create a simple alphabet book base on an augmented reality application to help young children to learn english words.

I had successfully managed to set up the application with the help from https://ar.qualcomm.at/qdevnet/sdk/ios

However, I am facing a problem with the sound input. I am trying to input audio to this application whereby, eg. for alphabet A, iPhone detects the marker for alphabet A, and then output a 3D Apple image to indicate that it is an Apple. But I would like to input an audio voice to pronounce the word Apple along the way, is it possible to do that? If so, how?

Currently my script looks like this

---

using UnityEngine;

// A custom handler that implements the ITrackableEventHandler interface.

public class TrackableEventHandler : MonoBehaviour, ITrackableEventHandler{

AudioSource asrc;

 #region PRIVATE_MEMBER_VARIABLES
 
 private TrackableBehaviour mTrackableBehaviour;
 
 #endregion // PRIVATE_MEMBER_VARIABLES



 #region UNTIY_MONOBEHAVIOUR_METHODS
 
 void Start()
 {

asrc = GetComponent(typeof(AudioSource)) as AudioSource;

     mTrackableBehaviour = GetComponent<TrackableBehaviour>();
     if (mTrackableBehaviour)
     {
         mTrackableBehaviour.RegisterTrackableEventHandler(this);
     }

     OnTrackingLost();
 }

 #endregion // UNTIY_MONOBEHAVIOUR_METHODS



 #region PUBLIC_METHODS

 // Implementation of the ITrackableEventHandler function called when the
 // tracking state changes.
 public void OnTrackableStateChanged(
                                 TrackableBehaviour.Status previousStatus,
                                 TrackableBehaviour.Status newStatus)
 {
     if (newStatus == TrackableBehaviour.Status.DETECTED ||
         newStatus == TrackableBehaviour.Status.TRACKED)
     {
         OnTrackingFound();
     }
     else
     {
         OnTrackingLost();
     }
 }

 #endregion // PUBLIC_METHODS



 #region PRIVATE_METHODS


 private void OnTrackingFound()
 {

asrc.Play();

     Renderer[] rendererComponents = GetComponentsInChildren<Renderer>();
     
     // Enable rendering:
     foreach (Renderer component in rendererComponents) {
         component.enabled = true;

     }
     Debug.Log("Trackable " + mTrackableBehaviour.TrackableName + " found");
 }


 private void OnTrackingLost()
 {
     Renderer[] rendererComponents = GetComponentsInChildren<Renderer>();

     // Disable rendering:
     foreach (Renderer component in rendererComponents) {
         component.enabled = false;
     }

     Debug.Log("Trackable " + mTrackableBehaviour.TrackableName + " lost");
 }

 #endregion // PRIVATE_METHODS

}

---

The codes in bold are the codes I tried to add myself. I had already attach an AudioSource to the object I want to make the sound, and also loaded a sound clip into the audio source. But it is still not working ): any help?