I withdraw my endorsement of Audio-Technica's ATH-ANC1 headphones.
Barely a year after I bought and first wrote about them, one earphone broke free from the headband; when I temporarily fixed this with electrical tape I was rewarded with about two weeks of additional service before the other earphone failed in exactly the same way. More galling than Audio-Technica's lack of attention to fatigue design, however, was their lack of attention to customer service—representatives of the company refused to make any replacement parts available and, since I was just outside of the warranty period, insisted I send them my headphones and pay more than half the price of a new unit to have them repaired. Nonsense!
Instead of dealing with Audio-Technica anymore, I took this as an opportunity to try out a technique I read about in Make magazine: fixing delicate plastic parts, such as the broken bridge of an eyeglass frame, by wrapping the joint with thread and coating it in epoxy, making a kind of thread-reinforced composite.
First I glued the fractured surfaces on both sides back together with a bit of epoxy and let this set overnight. Then I tied a bit of black thread onto the headband (using a constrictor knot, although a surgeon's knot is probably the best choice) and proceeded to wind this thread over a length of about 3/4 inch, making sure that many of the windings passed back and forth diagonally across the fracture. Once done I tied the other end of the thread tight onto the headband and coated it thoroughly in epoxy.
The repairs don't strike the eye too obnoxiously and so far they're surviving well. My only complaint, aside from the replacement-parts policy of Audio-Technica, is that I had to sacrifice the foldability of these headphones to make the repair, since both sides failed so close to the hinge. No matter, I'll just remove them from traveling service; I mostly use them in the office anyway. Many thanks to Dmitri Monk for sharing this useful technique in the pages of Make; please don't hold him responsible for the relatively sloppy job I did!