By turning off the voices.
"But Ethetan, how will I hear discussions about mudcrabs?"
I rest my case. Seriously, with no voices, one can easily forget that only 6 VA'a voice the whole of cyrodil. Stealth is also moderatly improved as no longer can I hear the "Hello, who's there" line from patrolling grunts. If you're an immersion junkie I highly suggest turning voices off. I wish I had done this 6 years ago.
In addition, playing with no music, crosshair, and putting a black piece of paper over the compass help a lot. Yeah Im on console lol.