Iphone6- Siri constantly starting up, interrupting, turned siri off, then voice command did the same. appeared when i used a $9 set of integrated microphone earbuds. Took those out, Siri & Voice command problem stopped. It COULD be dirt in the earphone jack. Lot of dusty work last few days. maybe those earbuds. My quickest bet would be the compressed air treatment mentioned above. For the random mid-night siri attacks, internal mic/cable/connector parts seem more likely. Thanks!