Quick tips in "Things to make and do". A while ago I bought some "noise cancelling" headphones. A common misconception is that these are useful for reducing ambient noise, like conversations. But, that's not how they work. Rather, they analyze various regular background noises (ideally, low frequency), and attempt to cancel the *next* instance of these. An ideal application is on an aeroplane, where there is a continual rumble of engines and air conditioning. I tried these on a few flights, and although the effect was noticeable, there still remained a fair amount of rumbling not removed. So I stopped bothering to bring the headphones with me on trips.
On a recent flight, I instead improvised my own replacement. I often carry earplugs with me. They help me sleep through all kinds of annoyances, such as telephone calls, alarm clocks, fire alarms and the like. I especially recommend them for long flights: the aforementioned rumbling of the plane often leads to headaches, and the earplugs are quite effective at reducing this. On this flight, I still wanted to listen to the inflight movie. Instead of bothering to remove the earplugs, I just left them in, and put the airline provided headphones on over the top, and cranked the volume up. This turned out to be quite effective: I could hear the film fine, and the rest of the noise was mostly blocked out. Score! Now you too can make your own noise-cancelling headphones for a fraction of the price!