Are smart assistants always listening?

Tech expert Peter Cowley answered Katie's question...

Peter - So in principle we're told smart devices are just listening for so-called “wake words” which could be Siri or Okay Google or Alexa or Amazon etc, and you can prove that. If you switch off the Wi-Fi, you'll find that it wakes up the device and it goes “urgh, what do I do now?”.

So this is because there isn't enough processing power, space capability, to actually do the analysis inside the device. So once woken it will then connect itself to servers somewhere your Amazon servers Apple servers or whatever, which will take the data, work out what you're trying to say and then work out what the answer is. So in principle certainly I'm pretty confident that in general, only when it's woken, will it talk to the servers.

However there is evidence that came out a few months ago that some of the data that is recorded and listened to after it's woken up. I tend to believe that they're not transferring or listening to the data the whole time. So in principle, yes, I would trust them that they're not listening the whole time.