I work with a child that has hearing difficulties as well as intelligibility issues. Are there any apps that use voice to text as well as text to voice in the same app?

I work in an elementary school and have been working with a child who has had hearing issues since the age of 2. This has greatly affected his intelligibility. On top of that, his hearing is so compromised that he isn't able to understand what is going on in the classroom. He is in need of surgery, but even with this and/or hearing aides, they don't expect his hearing to improve. He has very high intelligence and does very well in school despite his difficulty with hearing and intelligibility. He is able to communicate through writing, but often will just shake his head or smile because he isn't able to understand what people are saying. As he is growing older his difficulties are greatly affecting his interactions with peers. There is also a concern that if we don't find an assistive technology to help him out, he may not be able to reach his highest potential. What I think may help is a program that provides the ability for him to use a text to speech so he can be understood, but also something that can put what others say into text so he is able to read what they are saying. I'm wondering if there is an app out there for him? If you could please help me out, I would greatly appreciate it!

thanks