So, you're Deaf or hard of hearing and you want to watch a Twitch streamer without missing out on everything they're saying.
Ideally, the Twitch streamer you're watching will have a plugin like Twitch Captions or OBS captions plugin which both use Twitch.tv's CC feature so the captions can be toggled on/off for users who don't want them. Alternatively, they can even have closed captions