I took my GMAT in the US [Kansas] and they allowed ear plugs. I visited the test center in Kuwait and when I asked them whether they allow for ear plugs, they actually gave me a brand new one right away just to try it before deciding to take the test ! they were really generous. It seems like not a lot of people take the GMAT over here. The test center is also responsible for TOEFL, GRE, and a bunch of other tests.
The test center is located in the Downtown in a really nice building. I guess it's hard to imagine a downtown with nice buildings in Kuwait

. Trust me, the test center is not a large tent in the middle of the desert