Alexa and iPhones with Siri enabled, and Android phones, are all continuously listening with their microphones for their wake word, unless you've specifically t

Alexa and iPhones with Siri enabled, and Android phones, are all continuously listening with their microphones for their wake word, unless you've specifically turned the feature off. The difference is that the Alexa connects to your wifi, so if you wanted to, you could trivially tell if it's communicating when it shouldn't be. When I worked at Amazon, I was given the impression that the system that handles detecting the wake word was implemented in hardware, and the software system that does the real speech recognition doesn't "wake up" or gain access to the audio channel unless the wake word is detected by that hardware system -- and it's very obvious when you've woken it up (the colored ring lights up, it speaks, etc.) Echo devices also sit in one room. If you're like most people you take your phone everywhere, which means that if it's spying on you, it could literally have a transcript of every word you spoke the entire day, as well as any people you've been around. To make matters worse, it would be difficult to tell if that was happening. Unless you're an uber-hacker who knows how to root an iPhone, or a radio geek who knows enough to monitor their device's cellular transmissions, good luck figuring out whether Siri is listening to and passing on audio that it shouldn't. The problem is that phones have so many apps and responsibilities -- given that they are essentially full computers -- these days that nonstop data transfer on a wifi network from my phone wouldn't be alarming: it might be backing up pictures to a cloud, or syncing the latest version of apps, etc. I think the dedicated devices like Echo/Alexa are what you should buy if you're the most privacy-sensitive, since they have zero reason to be uploading to the Internet unless you're actively talking to them, and they have zero reason to be downloading unless they're receiving a software patch, which should be very rare. And because they're on your wifi (not cell) you can monitor their network traffic very easily.