Here's a decent explanation: https://hackernoon.com/how-does-hey-siri-work-without-your-iphone-listening-to-you-at-all-times-827932do https://hackernoon.com/how

Here's a decent explanation: https://hackernoon.com/how-does-hey-siri-work-without-your-iphone-listening-to-you-at-all-times-827932do https://hackernoon.com/how-does-hey-siri-work-without-your-i... Basically the microphone 'listens' for an audible key using the co-processor, but doesn't 'hear' or record anything, there's no audio information being written to disk or memory.