Have you spoken with him about what he'd like? I think everyone has different tastes (both personal and also in relation to the types of hearing loss they have) and one of my buttons in particular is when people go out of their way to do everything... except ask what I prefer. For example, if he prefers to do video chats (I myself do), he may appreciate hand raising/visual cues before speaking (to context switch), cl…
check in with your manager and hrbp before doing so though. you don't want to step on any laws or toes. (and hr may already have a program in place to help)