I am flying quite a bit and working in a lot of computer rooms and want something for those areas. In general I use some foamy 29 or 31 db rated earplugs for those areas. I have also found that combining my triplefi with a set of Comply Foam Tx500 tips they are nearly as good as earplugs at sound isolation. How does noise canceling headphone stack up against these? I just can't find anything in my area to test out, let alone just plain buy.