It sounds like you might like these little gadgets.

When they say Exceptional noise isolation they mean uses noise cancellation to cuts out all background noise. I know very demanding people who swear by them.

So put them on, put on some John Cage, and code in peace. :-)

UPDATE: I looked at their advertising a little more, and I am not so sure that they use active noise cancellation. I think they just are effectively very good earplugs with speakers inside them.