using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public AudioSource MyAudioSource; //put your object in inspector that have the audio
void Update(){
if (Input.GetKeyDown(KeyCode.Escape)) //When press ESC to pause the game { if (Time.timeScale == 0) { MyAudioSource.Stop(); } else { MyAudioSource.Play(); } } }

audioSource.Play();//Start playing
audioSource.Stop();//Stop playing