The goal of providing accommodations in any situation is to try and provide a level playing field for all students. The goal is not to give advantageous consideration or perferential treatment to an individual student. Students with disabilities may require specific accommodations in order to perform on a level with their non-disabled peers.
All students are individuals with unique needs.
Hard of hearing students can no more be stereotyped than can hearing students. Some hard of hearing students may need no accommodations with regard to testing while others may require specific modifications. It is very difficult to make generalizations. However, there are some standard accommodations, which many hard of hearing students find helpful. Students are generally allowed either time and a half or double time for a test.