I am profoundly deaf, always have been. Because of that, I do not finesse my way into better paying jobs through brown nosing and knowing the right people to feel up for the promotion. I totally suck at it, so I have had opportunities severely limited to me, so the best I could do was work office or retail jobs, and stay stuck there. I've been on SSDI continuously since 2005, and from time to time before that dating back to 1998.
I finally decided I had enough of that and fought my way out of the city environment, which took 5 years of reading, studying, and learning from underground financial information (meaning info that the Financial Mob based out of NYC don't tell you about, like the stock market is really rigged to fail you, paper money, the New Great Game underway around the world, etc. - if you read stuff from GATA, Ed Steer's Daily, know names like James Turk or Ted Butler, you know exactly what I'm talking about) to determine how to break out of the typical American occupational profile, which is basically unskilled jobs in the cities. I needed to get into areas of food production, mining, resource extraction, or manufacturing. I decided on farming, since without farming/growing food, there is NO civilization that can exist at the current level without it. I might even specialize in GROWING SOIL, which is something even most organic farmers are still not thinking about.
Given that, I have SSDI and look for ways to make money to supplement that income, like working at renaissance/medieval faires (my home faire is Sherwood Forest Faire just north of Bastrop) or volunteering on the farm for a reimbursement stipend, all the produce I would eat on a given day, and free rent and utilities for my travel trailer. It's working out pretty well, if I can just get a handle on all these functional emergencies on my used travel trailer (had to replace my toilet's water module assembly today, and watching my hot water heater's tendency to stop the pilot light every 1 to 3 days).
In regards to qualifying for disability based on deafness, I think that when you pass a threshold for "how deaf" you are, you are AUTOMATICALLY granted SSDI under certain scenarios, like your income level and job history, etc. Lots of people, having lost their hearing later in life, tend to not fall in that category I find myself in.