There's an easy test that applies to yourself only though. Go to a place without tv/internet/books (electricity is fine) for a week, where you exercise outdoors and spend time with people.
I always end up sleeping 2-3h more (from 6h regularly to 9h!), wake up earlier, and sleep earlier - and in fact, feel better.
Most of the rest is just the stress inducing work/city life most of us zombies "have" to go through.
I probally got the facts/study wrong, but heard something like this lately. Too lazy to look it up. I don't think they had a control group.
I don't know if it's my damaged brain, or I've just become conditioned to the noise in society. I can go to sleep, or relax in complete silence. I need a radio, or TV on in order to sleep. To be honest, I need background noise in order to read, or code. The only time I have overcome my wandering thoughts, when in silence(when I think about it--nature is filled with sounds.) is on rigrious outdoor adventures, but they have to be rigrious--like back packing, and river rafting(trips where I need to do most of the work. The paid for trips--I'm not tired enough to sleep. My mind just wanders, and I'm up, and tired the next day.)