Should Have Used Plugs

In reply to my story of Travelling Tired, Dave Aronson e-mails:
While noise-cancelling headphones cut the engine noise nicely, as you've discovered they don't do so well on non-predictable noise like screaming babies, overly verbal people, etc.  That's where *earplugs* come in.  I've seen cheap disposable foam plugs with up to about 35 dB of reduction, available in drug stores, gun stores/ranges, and probably other places you can think of.  Still an incomplete solution, but much better than headphones alone, and not very uncomfortable once you get used to having something inside your ear. I even use them when sleeping at hotels, and sometimes when I have trouble sleeping at home and there's any noticeable noise.  There's something very relaxing about hearing (almost) nothing but your own breathing.
As for Mrs. Colonoscopy, maybe you could have switched seats with her. Though you might have found a window seat a bit narrow (IIRC you're a bit large-framed), it might still be more restful than having to get out of your seat for her every half hour.
I wouldn't take the window seat away from the kid, and even if I did, my claustrophobia would have kicked in to the point where I couldn't sleep, anyway. But Dave is right about the foam ear plugs, which I have used and found highly effective. Unfortunately, I forgot to bring them on this trip.

It could have been worse. It could have been the day before this woman's colonoscopy which, as I have written, is the Day Of Hell No One Warns You About.