Every Echo is loaded with four separate algorithms, each trained to listen for one of the four wake words. Once you set a wake word, that specific algorithm is activated, meaning your Echo can truly only understand one word. Only when the ring of lights around the top of an Alexa device is illuminated is the device recording and sending the audio to Amazon’s servers.
Echoes have a limited amount of AI on the device; Alexa’s brains for answering questions live on Amazon’s cloud servers. All Alexa can do constantly is scan for a wake word, Prasad says. It’s as if your brain only knew one thing: the way “Alexa” sounded. No family, no birthdays, nothing more.
If you’re still paranoid, you can also check to see what Alexa has heard by opening the Alexa app, which contains a complete history of every utterance the associated device has ever stored.