How do phones constantly listen for voice commands like ‘Hey Siri’ or ‘Ok Google’ without draining the battery quickly?

Question

How do phones constantly listen for voice commands like ‘Hey Siri’ or ‘Ok Google’ without draining the battery quickly?

In: 255

Answer 1

Going to add to the above comments and say this is all done locally on the chip in the phone, it will only connect to the internet to “translate” the command after the initial wake up command of hey siri/ok Google happens.