On a recent in-house field trip I had the pleasure of working with a class of deaf, Deaf, and hard of hearing students. It was a good reminder on the difference between Deaf and deaf people:
Deaf people (with the capital D) identify with the culture that goes along with being unable to hear. Although they are by no means a monolith to be generalized, they often prefer signing over speaking and signing American Sign Language (ASL) over signed English. (Mental Floss wrote an excellent article on the 7 FAQs about sign). They have their own history, stories, and identity that comes from being in a minority culture.
Conversely, people who are deaf prefer to identify with the majority hearing culture. To teach a class with both groups present, one must use the language modality that reaches the majority of students (in this case simultaneous communication, or signing and speaking at the same time). But still make sure that every student has their language represented to encourage participation and understanding. It’s not as difficult as it sounds, we just put on silly hats and acted the afternoon away!