I have the Inside Ride E-Motion Rollers (love them!) and always run Continental GP4000 S II tires. I found that they are squeaky and have a buzzy vibration when new; due to the combination of the shiny, slick surface of a brand new tire and its associated tire “whiskers”. But once they’re worn, they quiet down a great deal. I can barely hear the tires over the sound from my drivetrain and the rollers themselves.
I found that it takes about a couple hundred miles of outdoor riding before they quiet down indoors. Swapping front↔rear will also help speed up the process. And whenever I bring my bike inside, I’ll wipe down the tire with a rubbing alcohol dampened rag.
As for pressure, I run mine at 82 PSI when riding rollers (I weigh 156lbs.). The 25mm GP4000 S II tires will measure 27.5mm wide when mounted on my Bontrager Aeolus 5 rims.
For outdoor riding, I’ll usually run 70 PSI front/73 PSI rear (lots of chip-seal around here) so I do increase the pressure when riding indoors, but only ~10 PSI.
Hope this helps!