Sign language interpreters at our church are placed in good visual lines to both read and see what is happening. More than one interpreter is needed, and they trade off, sometime with specialty in music for which they have been given words to an anthem or Bible reading for which they have been given advance references. Theological terms are different from regularly signed words, and references are available to help with this. Our church had several signing classes, and about eight persons became minimally proficient and some went on to do advanced study. If you hire interpreters, it costs from $100 up for a few hours, so this becomes a budget item for the general church rather than the worship budget. We also had a speech reading class that helped persons learn to place ideas under a topic for clues to what they were hearing.
Our minister uses big screen power point phrases and verses as illustration of his sermon. This helps speech readers understand categories and idea tags. Make sure the ministers face is well lighted and not in shadow.
A big need for persons with hearing impairments of any kind is socialization. Invite a group of persons who use sign language to lunch. Laugh at yourself at the awkward mistakes. The act of caring enough to do this sends a message of its own. Teach Sunday school teachers to use white board idea words and other visuals to help persons in their groups who are losing their hearing.
I hope this helps the persons who responded with questions on this topic.