As a vision impaired gamer, text chat is a big no for me in games, as I just can’t keep up with trying to read it. At least this way with it being read to me, it makes my life a bit easier when gaming.
Bibbo, via eurogamer.net

I really hope that this works well. It’s really tough playing with frinds online since I’m deaf.
A_Zombie1223, via Reddit

An incredibly useful piece of functionality for online communication would be real-time transcription between speech and text, allowing people to communicate according to their own preferences and receive communication according to their own preferences too, regardless of which method other players are using. It benefits people from all groups of impairment – difficulty seeing, reading and understanding text, typing, hearing other players’ speech, and speaking.

This presents some significant difficulties, and more than in other other media, particularly for the speech to text transcription. In-game chat can involve frantic and emotional speech, game-specific jargon (e.g. “equipping Mechaneer’s Tricksleeves) and gamer specific jargon (e.g. you noob), making accurate recognition extremely difficulty.

However even without completely accurate transcription it can still be an enabler, particularly between groups of friends who know how to adjust their communication style accordingly, and progress is being made, with the first step at this kind of functionality now available for Xbox and PC games as part of the Xbox SDK.

Best practice example: Halo Wars 2

More information: Accessibility functionality available in the Xbox SDK (video)