CrowdControl/Assets/ButtonSoundClick.cs

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

public class ButtonSoundClick : MonoBehaviour
{
    public AudioSource audioSource;
    public Button[] allButtons;
    private void Start()
    {
        Starter();
    }
    void Starter()
    {
        allButtons = FindObjectsOfType<Button>(true);
        for (int i = 0; i < allButtons.Length; i++)
        {
            allButtons[i].onClick.AddListener(() =>
            {
                PlayClickSound();
            });
        }
    }
    void PlayClickSound()
    {
        audioSource.Play();
    }
}