My Footstep isn't working

I wrote up this javascript and have no compiler errors, but when i walk i don’t hear any footstep sounds. What’s wrong? I tagged the objects correctly too.

var AudioTimer : float = 0;

var ConcreteSound: AudioClip;
var MetalSound: AudioClip;


function Update () {

	if(AudioTimer > 0){
	
	AudioTimer -= Time.deltaTime;
	
	}


	if(AudioTimer < 0){
	
	AudioTimer = 0;
	
	}
	


}



function OnControllerColliderHitt (col: ControllerColliderHit){

	if(col.gameObject.CompareTag("concrete") && Input.GetAxis("Vertical") && AudioTimer == 0 ||
	Input.GetAxis("Horizontal") && AudioTimer == 0 ){
	
	audio.clip = ConcreteSound;
	audio.PlayOneShot(ConcreteSound);
	AudioTimer = 0.5;
	
	}
	
	if(col.gameObject.CompareTag("metal") && Input.GetAxis("Vertical") && AudioTimer == 0 ||
	Input.GetAxis("Horizontal") && AudioTimer == 0 ){
	
	audio.clip = MetalSound;
	audio.PlayOneShot(MetalSound);
	AudioTimer = 0.5;
	
	}

}

OnControllerColliderHitt 2 t’s?

This is not going to work anyway, the character controller is a capsule over the whole character so it won’t do what you expect. It does not collide the feet. You may want to use isGrounded instead to check if you are …grounded.

All you need is to play a looping footstep sound while walking:

if(Input.GetAxis("Vertical")&& controller.isGrounded){
   //Movement
   audio.Play
}else 
   audio.Stop();

This is simplified version. Make sure your audio is looping. That could do it.
controller stands for the reference to your character controller.