Here's an article:

http://www.newscientist.com/news/news.jsp?id=ns99996073

So if plasma reduces jet noise, then can it reduce turbine noise?

There are gyroplanes like the one made by Groen Bros, and also the old
Fairy, which used ramjets on the rotortips to boost rpm and lift
during takeoff, but this caused terrible noise problems. Could this
plasma noise-deadening approach make the ramjet rotor-assist more
practical and feasible?