campfire/Assets/Scripts/CollisionSfx.cs

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

[RequireComponent(typeof(Rigidbody))]
public class CollisionSfx : MonoBehaviour {
    public LayerMask Mask;
    public AudioClip[] Clips;
    public AudioSource Source;
    public float EffectCooldown;
    [Tooltip("When the game starts, a lot of sticks drop (because they spawn). This is the amount of time that the stick should stay silent after spawning.")]
    public float WaitUntilSfxAtGameStart;

    private Rigidbody Body;
    private float LastTimePlayed = 0;

    private static float LastTimeGloballyPlayed = 0;
    private static readonly float GlobalCooldown = 0.05f;

    private void Awake() {
        Body = GetComponent<Rigidbody>();
    }

    private void Start() {
        LastTimePlayed = Time.time + WaitUntilSfxAtGameStart;
    }

    private bool PlaySound() {
        if (Time.time - LastTimePlayed >= EffectCooldown && Time.time - LastTimeGloballyPlayed >= GlobalCooldown) {
            LastTimePlayed = Time.time;
            LastTimeGloballyPlayed = Time.time;
            if (Clips.Length > 0) {
                Source.PlayOneShot(Clips[Random.Range(0, Clips.Length)], Mathf.Sqrt(Body.velocity.magnitude));
                return true;
            }
        }
        return false;
    }

    private void OnCollisionEnter(Collision collision) {
        if (((1 << collision.gameObject.layer) & Mask.value) != 0) {
            PlaySound();
        }
    }
}