My bose QC-35 II broke twice during the warranty period. Additionally, one of their temporary failures was that suddenly the music stopped and instead they froze while playing a very loud high pitched beep. It was so painful in my ears that I literally punched them off my head. I've been hesitant to use them since.

But this story, together with my own 2 warranty repairs, confirms my suspicion that Bose has serious QC issues.