They have to be listening all the time if you have voice activation. The mic always needs to be open so it knows when you say "hey siri" or "hey google". How would it know you said that if it didnt already listen to every word. The question is if that stays local on the device.
In that sense, yes, they are always listening. But that's a very small system that only compares like the last two seconds of audio against the stored model of the user saying "Alexa".
They have to be listening all the time if you have voice activation. The mic always needs to be open so it knows when you say "hey siri" or "hey google". How would it know you said that if it didnt already listen to every word. The question is if that stays local on the device.
In that sense, yes, they are always listening. But that's a very small system that only compares like the last two seconds of audio against the stored model of the user saying "Alexa".