Try to play a Netflix movie or show and have anything else going on around you and you won't even be able to hear it.
It's great with head phones on but I use this all the time for watching shows and movies while working out. Its so quiet I have to use headphones when I am on the treadmill or I cannot hear it playing while the treadmill is on.
I hope Microsoft addresses this on the next model.
Love my Surface Pro, it is by far the best device I have used so I can easily live with the sound issue.
If your are thinking about buying it, stop reading this, go to a store or order from their site and get one NOW.
I own a network technology company and handle IT support for a lot of companies and I can do everything on this (using it to type right now) that I could do with a full blown PC setup. I have also owned every tablet, laptop, and device that has ever come out so trust me when I say it is great.
This unit has replaced my Lenovo Yoga 13, and my Samsung Ativ 500 and 700 with no issues. I have also had every Samsung and Asus tablet and this is a bad boy. This also includes the Tab and Note series.