Audacity 2.1.12, OS X 10.10.5. All audio files that I import into Audible (mostly mp3) play perfectly when using my Mac’s built-in speakers. When I connect USB headphones (Microsoft LifeChat LX-6000) and direct Audacity to output to them, the playback distortion is so great it’s sometimes hard to know what I’m listening to. These same files, when imported into iTunes, play perfectly (including when I use those same Microsoft headphones). Yes, I read the “Why do I hear clicky playback on Mac OS X?” hint, but changing the Buffer Latency setting in succession from 0 through 100 msec in 10 msec steps did nothing. Is there any solution to this problem, other than abandoning OS X and working with Audacity on Windows?