If the idea is that the stutterer hears themselves speaking fluently, then almost all stutterers don't stutter when they are alone. I occasionally record myself speaking alone, I even sometimes put on my headphones and record myself pretending to be speaking on the phone while walking to home, funny thing is when someone is passing by, I start stuttering. I don't do it for a therapeutic reason, but I just like to live the dream of being a fluent speaker. As per AI tools, there are already some commercial tools available that take segments of your voice, then construct a bot for you (text-to-speech) that will say with your voice what you write to it, I think the exact name is (AI voice clone). I haven't tried any of them myself, but I saw it on YouTube, the clone has that slight robotic tone to it, but that was a year ago, I think with the rapid mind boggling advancements in AI, I bet there are tools out there now that sound indistinguishable from the real one. I imagine some applications of AI in stuttering, would be in something like a software that help the stutterer do speaking/breathing/relaxing exercises, and based on its intelligence, it will provide them feedback and ways to improve, it should overall serve as coach. However, I think the key takeaway in stuttering, is the presence of another human being, this is the whole problem.