That's a screen shot of this article at NBCNews.com and I chose to post the screenshot because of the poll at the lower right. Granted, this is a VERY small sample and the poll is unscientific at the very best. But: suspicions confirmed, eh?
I have other issues with this study, as well. While I feel the findings are more than accurate for hip-hop and its various permutations (i.e., too frickin' loud and sounding the same to the point of serious monotony) I feel that comparing Led Zep or The Stones to anyone from Motown or the Beach Boys, even, is a bridge way too far. By that I mean the study allegedly examined pop tunes all the way back to 1962, so you'd have to include artists like Sinatra, Herb Alpert, and Tony Bennett in that mix, too. They sound the same as Snoop Dog? Yeah, right.
YMMV, of course.
h/t: Shoebox blog.