By the time he was a young man, my father was already hard-of-hearing, particularly on the left side. Being left-handed, he thinks that a lifetime of holding shotgun and rifle stocks to the left shoulder and firing without hearing protection was the largest culprit. In any case, by the time I was in my late teens, my interpreting services were more and more required in social situations. Very naturally, my father had become a face-watcher and a lip-reader, but if approached from behind (especially behind and left), he often could not hear (and appeared to be ignoring) the speaker. Speakers talking too fast or using a different dialect were also a problem, so I became very handy at restaurants and on vacation. If he couldn't understand something, he simply looked at me questioningly, and I repeated or translated the statement/question. My face and my dialect were easy for him: he'd been reading me for years. Now, I'm 40, and my father is pretty much deaf without his hearing aids. Upon getting them, he said it was nice to hear birds again, but not so nice to listen to my mother shuffle around in her bedroom slippers, which he said sounded more like a herd of elephants sliding around the kitchen.
I tell this story to illustrate that I am sensitive to hearing issues, or at least I always thought I was. In the last year, I worked at a clinic were I had a regular client who happened to be deaf. And I was rather horrified one day when another therapist friend pulled me aside after observing part of my post-session interview and teased, "For God's sake Lynna, he's deaf, not stupid!" Apparently, I was gesturing too much, and exaggerating by speech too much. I was mortified, largely because I was afraid that my attempts at being helpful had back-fired on me, and my client was probably going home after each session thinking, "What a wacko . . . "
So I did some research. I had been gesturing a lot to help clarify my message: was that wrong? Survey says: not necessarily. Gestures are welcome when communicating with deaf people. After all, people with "normal" hearing use gestures all the time in conversation. HOWEVER, gesturing should be precise and kept at minimum. For example, pointing at the gravy when asking, "Would you like some gravy on your biscuits?" Too much gesturing is just distracting and may confuse the issue instead of clarifying it.
Should I speak slowly and hyper-enunciate? Survey says: only to a degree. I had been worried because my dialect (South Eastern US, etc.) is very different to that spoken in the Seattle area, and that can change the way some words are framed. BUT, according to several sources, one should simply try to be as clear with a deaf person as one would be with a hearing speaker from another region/dialect. Which means, if a hearing person would think you sound condescending or strange, a deaf person could interpret that same speech behavior that way as well.
The only other universal suggestions I found for communicating effectively with deaf people were (1) write things down legibly if you cannot express concepts well enough through speech (which I do) and (2) be mindful that facial hair does not block your mouth/lips (I don't have any). And I might add, I guess, (3) give yourself a break. My mortification smacked of perfectionism, but I well know I can never be perfect. I believe my client knew my intentions were pure even if my approach was muddy.