I went to the cinema to watch the 1st Alien film. There was a scene in the lab , not the chest busting one, but where they thought the critter in the test tube was a dead un.
The audio goes quiet and you can hear your heart beating. Your brain is yelling at you to prepare yourself for the jumpy moment. You kind of close your eyes but it's taking ages and you open them again just at the exact time the thing jerks to life and the soundtrack booms into your earlobes.
I screamed so loud people turned round to look at me