Script won't detect collision

Hello,

For about a week now i've been working on a 2D physics game where the objects will move according to the tilt of the device its ran on. Im done with physics but now im finishing particles, lighting and sounds. I have this script which will play a random of 3 hit sounds when a cube hits either another cube or a wall. The script doesn't give any warning or errors when the game is started but no sound plays when it collides with the floor. To make sure its not just the sound I added a debug.log in the first line but that never ran.

 using UnityEngine;
 
 public class RandomSound : MonoBehaviour
 {
     public AudioClip[] AudioClips;
 
     public void OnCollisionEnter(Collision collision)
     {
         Debug.Log("hit"); //check if working
         if (collision.relativeVelocity.magnitude > 1)
         {
             int CP = Random.Range(0, AudioClips.Length);
             GetComponent<AudioSource>().clip = AudioClips[CP];
             GetComponent<AudioSource>().Play();
         }
     }
 }