Why is this audio clip not working

if (col.gameObject.name == “Wall Right”){

audio.clip = _sfxList[0];

audio.Play();

}

ERROR
c:\Users\Derrick\Desktop\Unity Pong Stuff\2D PONG\Assets\PongPlay\Scripts\BallBehavior.cs(17,17): Error CS0029: Cannot implicitly convert type ‘System.Collections.Generic.List’ to ‘UnityEngine.AudioClip’ (CS0029) (Assembly-CSharp)

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;

public class BallBehavior : MonoBehaviour {
//Speed to be modfied in the Ispector

public float _speed = 2.2f;
public float _height = 1f;
public AudioClip_sfxList;