It would sound like a buzzing. You'll also hear the fuel rail pressurize in the engine bay. If there was something in the ignition system causing the car to not start (preventing spark), it would sound like the car would try to start, but not turn over. You can test for spark by removing a spark plug, put the wire on it, and touch the electrode to the valve cover...have a friend try to start the car...you should see a spark.