This is the ideal behind universal accessibility design. For instance, when you're in a loud and crowded place a person with average hearing abilities might have the same needs as a deaf person when watching a video. That's why museums regularly use open captions on video screens since they benefit everyone, not just the deaf.

As a side note, I bet this guy gets fantastic battery life out of his mobile device, since he can set the brightness to the lowest setting possible all the time. I guess I'm assuming that all that Siri and speaker amp usage doesn't drain the battery more.