I expected this new game updated subtitle options in four games, Halo 1 and Halo 4, both cutscene or cinematic and gameplay are excellent. However, Halo 2 n 3 don’t have subtitle while gameplay, cinematic subtitle is excellent. I hope 343 industries will help and fix it for hearing impaired people 
Thank you.
I too am hearing impaired and would like to have subtitles during gameplay.
Indeed, there should be subtitles during the gameplay. Subtitles are available for cut scenes though. I find it disappointing that Halo 3 doesn’t have subtitles during gameplay. Not sure if it’s a bug or something they missed.
Great the forum for subtitles issues related is starting to growing hope 343i will catch this
Yeah I have raise this AGAIN 'cos 343i has agreed to put Spanish dubbed voices but won’t do anything about in-game subtitles for HALO 2 & 3!
there is an option but I believe it is just buggy. I am not hearing impaired but sometimes it is just easier to read than to turn the volume way up.
I am not hearing impaired, but I find it much easier to read the subtitles than to hear dialogue in many games.
I was quite sad to see that the subtitles did not work in Halo 2/3 outside of cutscenes.
Playing Halo 4 I am glad to see that they are there.