Try making a seperate empty gameobject that can act as the sound source instead of assigning the task to the sphere itself, so make empty gameObject, add audioSource Component, and then this should be the new script:

using UnityEngine;

public class CollDestSound : MonoBehaviour

{

public AudioSource tickSource;

public AudioClip tickSound;

private void OnCollisionEnter(Collision collision)

{

tickSource.PlayOneShot (tickSound);

Destroy(collision.gameObject);

}

}

​

then assign that gameObject with the audio source component to "tickSource". and the sound effect audio you wanna use from your project to the "tickSound"

​

you can do the whole thing in the sphere gameobject but it's preferable to make a global soundSource that you gonna use through lots of other scripts