What is the monobehavior code do i need to play a sound when my character runs into a wall?

I am new with Unity and I need some guidance. I have taken a cube and built a maze by extruding the walls from the flattened cube and dissected. So, the whole cube is a now a room with walls, etc. I am trying to paly a sound every time I run into the wall. I can get it play only one time when by FPC collides on start up of the game.

Could you help me find the right code to play a sound when I walk into a wall, reset and then play it again if I walk into a wall again?

Directly from Unity Docs (With some minor changes) :

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
	AudioSource audio;
	
	void Start() {
		audio = GetComponent<AudioSource>();
	}
	
    void OnCollisionEnter(Collision collision) {
        if (collision.name == "Wall")
            audio.Play();
        
    }
}