19. The Majority Of The Sound Was Recorded In Post-Production
T2 rightly won Oscars for both Best Sound (better known as Best Sound Mixing today), and Best Sound Editing, but the movie's dynamic soundscape proves all the more impressive considering that most of it was actually created during post-production.
According to sound supervisor Gloria S. Borders, roughly 70% of the film's dialogue was re-recorded during ADR dubbing sessions, due to the high-octane nature of the shoot rendering much of the on-set dialogue inaudible.
And while it's not uncommon for action movies to create most of the prominent sound effects during post, on T2 this even included minor sounds like the T-800's (Arnold Schwarzenegger) jacket creaking as it moves, and so on.
In fact, Sarah Connor's (Linda Hamilton) entire escape from Pescadero State Hospital features no on-set audio whatsoever, all of it having been replaced during post.
As for the movie's many, many weapons, Cameron wanted them to sound "hyper-real," and so had the on-set sounds replaced with more distinctive ones, like the shotgun blasts being switched out for cannon fire.
It's a testament to the mind-boggling craft on display that T2 remains a sonic marvel today despite so much of the live audio being basically unusable.