It is not squeak. It is the sound of doors creaking. Doors make the creaking sound when it is old, rusty or you haven't oiled it properly.
You get a lot of friction and there's a lot more of friction when two things are stationary than when they're moving. So, essentially the two bits of the hinge lock together, then the hinge bends a bit and then the force gets enough for it break and it jumps forward a bit and then it stops and then bends a bit and it jumps forward.
This jumping can happen at a range of pitches, including the horrible 50-100 Hertz range. As you're getting jump, jump, jump, jump, what you hear is the horrible creaking noise.