Ah.. QC35 I and QC35 II, the headphones that won't turn off, but Bose refuses to make it right for the users:
https://community.bose.com/t5/Around-On-Ear-Headphones/QC-35...
Note, the "solution" is buy new headphones if yours are our out of warranty.
https://www.youtube.com/watch?v=0bugTnRbnhQ&feature=youtu.be