For my case, the center also administers other tests, such as TOEFL, GRE, etc. And the timings for all the tests are pretty similar (if not exactly the same). So you find a lot of test-takers coming in at about the same time to register, read the T&C, etc at the reception area.
From the reception area, all the test takers (regardless of the type of test) is individually guided into the same testing area. Each is assigned to a particular terminal to take the test. Once you are seated, you begin the test. So during the initially part of the test, you find that there is quite a bit of movement behind you, especially if you are among the first to go into the testing area. This happened to me. But I guess the good thing is that you will finish your test earlier, so there is less movement behind you towards the end of the test.
I took my test in Singapore. You may want to call up your test center to check.