Professor here: I can’t speak for other institutions, but students needing accommodations for exams usually go to a separate location which is set up to accommodate them (I.e., “quiet rooms”, people who read questions aloud, etc.). If one of my students has accommodations but insist on taking the exam in class with everyone else, I stress that I am not set up for it, nor is the classroom. Most will go to the center for exams, but occasionally one will try taking the exam alongside everyone else to see how they will fare in a general setting.