Being a teacher who can't always speak

Today, I did something that's kinda hard, and kinda scary, and kinda risky. I told the department chair (so basically my boss, because I'm a teaching assistant and he's also coordinating the course I'm teaching) that I'm not always able to speak. I also told him what my backup plan is for those times (it's a pretty good backup.)

It went fine, by the way.

But I wanted to write a bit about what I think made me so lucky there, because there's some things I was able to pull off that not every disabled person can do, and these are relevant things! And it's not fair, and it deserves talking about. So does the fact that even with all the things I have working in my favor, it wasn't actually guaranteed that I'd get the good result I got.

Thing the first: I did my undergrad partially in this department (and partially in other departments in the same school.) That means that everyone in the department already knew who I was, and most of them actually knew me. I was that freshman who somehow managed to end up tutoring Real Analysis. What this means is that I got the chance to prove my ability as a tutor and as a student before anyone knew that the disabled side also exists.

Thing the second: I don't have big bulky tech that is obviously coded as "for disabled people" on my person... ever. My text to speech is on my laptop, which is a pretty common thing for a college student or grad student to own and carry with them. This means that my assistive tech's status as helping me with an aspect of my disability isn't clear until I start using it for that. I do a lot of other things with my laptop, same as most students do a lot of things with their laptops.

Thing the third: While someone who knows common traits and has a good idea what the tip-offs are for autistic adults will find me not even a little bit subtle, most people don't immediately know that I'm disabled upon talking to me. If they could tell immediately, my "pass for a little bit, then mention that I'm disabled a bit before I need any accommodations" method would be impossible to actually do.

Thing the fourth: I got lucky. Even when all the other things line up well, luck of the draw is still huge. (Luck of the draw may not be enough when the other stuff doesn't line up.) My department chair's initial reaction was to ask what he/the department would be able to do to help, and that I should let them know if I needed anything. I actually don't need much from them: I need them to not take issue if they see me using my text-to-speech in the classroom or if they find out about my using it. I need them to have my back if someone else takes issue with the use of text-to-speech.

What I've got:

1. Departmental not-taking issue and backup if someone else takes issue.
2. Offer that if speech is kaput I can text the office and they'll send another TA over if needed. (Probably not needed, the point of my backup methods is that I can keep teaching even is speech goes kaput.)
3. Statement that if my classroom's speakers turn out to be randomly incompatible with my text to speech/audio output, they'll get me moved into a classroom with compatible speakers. 

That's actually more than I asked for, but it's all stuff that's a good idea on their part. I want to get it in writing because a big piece of this was crossing my t's and dotting my i's to cover my hide from any potential students taking issue, so I will want to talk to disability services, but yeah. Seems to be working OK in my case, and my main issue is "So the solutions on the practicality side all exist, why is this sort of thing unusual enough that none of the classroom media assistance people had heard of sticking text-to-speech into the audio system?" My secondary issue is "So um maybe enough education that the phone isn't the first method of contact suggested for the event of speech going kaput would be good?" Because that was suggested before texting was, and if I can't speak, I can't phone. (Not that I do well with phones when I can speak, but...)