I did a game jam for blind gamers recently. Was interesting to start designing from the sound up. Some entries used recorded dialogue that you could interact with using keys. Others places sounds and speech on objects in a 3d space so you could move towards them with a first person controller using your ears. In general, I find it is good to have one audio source per game object so that you can manipulate the pitch, stereo position easily in the inspector (Unity). Other general tips would be to convert your audio files to ogg, and avoid long audio clips.
These are the submissions from the jam: https://itch.io/jam/games-for-blind-gamers-2/entries It was called Games for Blind Gamers 2.