 Lucasfilm showed Shin the finished product, having followed his suggestions to use an X-Acto knife to give the lightsaber a very sharp look, and to have sound accompany the weapon's movements.The lightsaber sound effect was developed by sound designer Ben Burtt as a combination of the hum of idling interlock motors in aged movie projectors and interference caused by a television set on a shieldless microphone.Burtt discovered the latter accidentally as he was looking for a buzzing, sparking sound to add to the projector-motor hum.