Apple's iPhone 6s has introduced an untethered 'Hey Siri' feature which allows for always-listening functionality even when the device isn't charging, by utilizing the power-efficient M9 motion coprocessor to always listen for voice commands.
But as AppleInsider finds out, the handset automatically switches off untethered 'Hey Siri' when it's in your pocket or face down on a table.
This is another trick in Apple's arsenal of technologies to extend battery life.