As you play you will see these small boxes on walls around the levels (they flash orange like collectibles) which you can access and change the environment re lighting, speaker, access, etc.
The first time I came across them was at the start of level 3 when you arrive in the tram hub (there are 2 at opposite sides in the tram central area - one is on the opposite wall from the save point).
You have to access 10 different ones so can't use the vent trick of just backing out and reusing it, but that said there are plenty of rewires around - I got this towards the end of level 4.
Good luck!