Just to throw out another option... I had the original Bose QC headphones, and what always bothered me was they just cancelled airplane engine noise (so you could hear the baby crying behind you even more clearly).

I got some in-ear Shure 'phones (forget the model number) that are basically an earplug with an embedded speaker.

Sound better than Bose, cheaper, lighter and don't need batteries, AND you don't hear babies or annoying conversations. I think several companies make a similar thing and they might be worth investigating. I've loved them way more than my bulky old Bose.