A lot of people will think sound in movie is recorded from the actual shooting. However it is not true. Whenever we film movie or even drama, the sound recording at the spot will only focus on the dialogue. So what the production team have to do is to reproduce the sound after editing. What I mean about sound is the sound of everything, not only just those imaginary sound effects from sci-fi film, but also every details of it. Watch the video below and you will know. When I watching it, it reminds me of my sound class during uni. So much memory about it...