I use earplugs. They are cheap, comfortable e doesn't damage your ears. I started to use them when there was some construction work in my street. But I started to like it so much that now I use them on the plane, the bus, to sleep, and to work. 3M sells some cheap ones: http://solutions.3m.co.uk/wps/portal/3M/en_GB/PPE_SafetySolu...

The problems are: People won't notice you are using it, and start talking to you from your back. That's a sure way to get weird looking faces from your colleagues.