Am really looking forward to the day when these kinds of features are available as Web APIs in the browser.
In relation to this, the open source project cboard (https://www.cboard.io/) is a very nice AAC web app where you can add custom cards with your own voice recordings. I am very grateful that there exist open source technology in this field as the commercial solutions are pretty expensive, and everyone should have access to a voice
I hadn't thought of doing it before this comment thread, and like you (and like most people I think, or at least many) find hearing recordings of myself speaking uncomfortable - because it doesn't sound like the same voice as I hear when I speak - but my reaction was "why hadn't I thought of that, I hope they reply to the comment asking how with an answer that tells me it's easy and cheap with instructions!"
More because, as bad as the hypothetical possibility of losing the ability to speak already is, wouldn't it be better to not also lose how you sound to everyone else in the world? You'd soon get used to the new way you hear it, or at least as soon as you'd get used to having a completely novel voice!