In my latest Appliance Science column, I look into how Amazon’s Alexa service captures your voice and translates this into commands.

There are plenty of things in my house that I yell at. Some of them answer back these days, though, and even do what I ask. My dog is still a work in progress as far as that goes, but my Amazon Echo has just about nailed it. The Echo is a device that uses speech recognition to perform an ever-growing range of tasks on command. Amazon calls the built-in brains of this device “Alexa,” and she* is the thing that makes it work.