In my experience, this is normal, though I think the valve train is just as noisy... but the rest of the engine gets louder
, at least my exhaust sure does....
If its adjusted properly, the valve train should be a little noisy, kinda like a sewing machine sound or mice w/ typewriters. If the valve train is quiet, the the valves have gotten tight and need adjusting.
If you haven't adjusted the valves, or don't know when they were last done, its probably worth checking... then you know their state. IIRC, they should be done every 5000 miles or so anyway.
A