Audio problem: When the crew are getting into the land rover tractor after the captain chews out his crew for letting the alien onboard, you can hear the "steel" door close with a heavy obvious metallic clang. A few seconds later the same door closes with a soft plywood thud, and a few seconds later it closes with no sound at all as if light as a feather. (00:36:00)

Forbidden Planet (1956)
1 audio problem - chronological order
Directed by: Fred M. Wilcox
Starring: Leslie Nielsen, Walter Pidgeon, Anne Francis, Warren Stevens
Continuity mistake: During the alien's assault on the ship, one crewman is seen near the spaceship's stairs firing a weapon. However, the weapon is pointed at a forty-five to sixty degree angle - at this angle, he would hit the bottom of the ship, not the alien that is much farther out.
Lt. 'Doc' Ostrow: You ought to see my new mind... it's up there in lights.
Trivia: This movie was based on William Shakespeare's play "The Tempest."
Question: Can someone explain how all the special effects were done, such as the electronic blasters rays, and the sound effects? As the film was from 1956 there were no electronic keyboards then and the sounds are very futuristic.





Answer: Many of the sound effects use an electictronic instrument called a theremin which was invented in 1919. You may hear it used more musically in The Beach Boys song "Good Vibrations." The visual effects would have been animated composites as used in Star Wars and Ghostbusters.
Myridon