Problem Detecting 2D Collisions

The idea is that when a gameobject enters an empty gameobject’s box collider, it will play a sound. However I am struggling to even detect collisions between the two objects!

Here is the setup of the empty game object:
alt text

And here is the gameobject which is colliding with it:
alt text

This is the code I am using for detecting collisions:

using UnityEngine;
using System.Collections;

public class playEricSound : MonoBehaviour {

	public AudioClip eric;

	void OnCollisionEnter2D (Collision2D collide) {
		print ("Collide");

Thanks for your help! If you need anything else, just ask!

So hard to see clearly in the screenshot!

But from what I can see, you forgot to add the rigidbody component to either of those sprites (need that component + collider for all sprites that you want to use the physics engine with).