Phew, okay Nonnie!
Please note: I am both sighted and hearing. I am not a part of the deaf/HOH community, nor am I vision-impaired. I would like to support these communities, not foster misconceptions and prejudices. Though I do try not to, I may misstep, and for that I am sorry. If anyone from these communities would like to chime in, correct me, or add to these ideas, I would be overjoyed to read it.
One of the things we have from canon that I absolutely love is that Dwarves have a sign-language that is universally known throughout their entire society – hearing or otherwise. This is something that we as humans really ought to emulate, I feel! There’s no communication barrier for any Dwarf who is deaf or mute, none at all.
I actually headcanon the great craftsman Telchar as deaf. I think he preferred not to speak, as he had something of an atypical voice, and used Iglishmek as his primary means of communication.
For deaf and HOH Dwarves who do still wish to use speech as a primary form of communication, horns such as Oin’s could be used. There might also be ear-trumpets that can be worn on the head, leaving the hands free: Dwarves are so mechanically clever, I don’t see why such things wouldn’t be investigated.
Blind and visually-impaired Dwarves might have a better stone-sense than sighted Dwarves, and therefore would be superior cavers and spelunkers. I feel that service animals would be an option for these Dwarves, too: goats, pigs, even small portable nimble burrowing creatures such as ferrets might be trained. Ravens too – very desirable as a service animal due to their speech abilities and their intelligence – but with an unfortunate fixation on carrion!
I don’t think there would be the emphasis on ‘special education’ units that there is in our world, holding these Dwarves apart from mainstream education. I think it would be entirely integrated. It would make sense for a teacher to sign in Iglishmek at the same time as speaking. It would make sense for Dwarves to have physical and touchable examples of concepts, being such an artisan race. Also – Cirth runes were preferred by Dwarves because they were easier to carve. Carved runes would be readable by hand, with practice… I think?
Anyway, there’s some ideas, Nonnie!

