Are students proficient in more than one language required to speak English in an all English speaking classroom during instruction?

I don't think that students speaking to each other should be required to speak English if they are not disturbing the class or interupting the lecture.  I would think that would be a matter of common courtesy.  However, in college or university, the professor may have his or her own rules in the class.  For example, I teach a night class from 6-9 pm.  It does not bother me if my students bring food and eat quietly during class because I know they work during the day, have driven to class, and otherwise might not get a chance to eat.  If a student brought crunchy chips, or noisy wrappers, I might ask that they not eat during class so as not to disturb other students.  I think that would be my right in the class I am teaching.  If not speaking English has become an issue, ask the person teaching why it is an issue, and what can be done to resolve it.