audio playing twice and not playing the way its in original mp3 file

I am using this audio clip from Shell Falling Sounds | Effects | Sound Bites | Sound Clips from SoundBible.com

The audio clip plays twice in my game. Ideally it should play exactly it plays in the .mp3 file. What I want is that it should play only once when it hits the floor(onCollisionEnter)

here’s the script attached to bullet shell

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

[RequireComponent(typeof(ConstantForce))]
[RequireComponent(typeof(AudioSource))]

public class bulletShell : MonoBehaviour {

	public Vector3 turnForce; 
	private ConstantForce forceComponent; 
	private AudioSource shellClip; 

	/// Awake is called when the script instance is being loaded.
	void Awake() {
		forceComponent = GetComponent<ConstantForce>();
		shellClip = GetComponent<AudioSource>();

		turnForce.x = Random.Range(-180, 180);
		turnForce.y = Random.Range(-180, 180);
		// turnForce.z = Random.Range(-200, 200); 

		forceComponent.torque = turnForce; 
	}
	
	void OnCollisionEnter(Collision col) {
		Debug.Log("I touched the ground"); 
		shellClip.Play(); 
		Destroy(gameObject, 3f);
		forceComponent.enabled = false; 	
	}
}

Go to your AdudioSource and uncheck “PLayOnAwake”