I know someone with this job. I don’t think it’s advertised anywhere as such. But it appears the role is called “data associate” or “speech and language annotator”. Basically they listen to the phrase after the keyword and then the response, marking whether or not it was helpful (maybe more detailed than that, not sure). It’s a data labeling job in some shape or form. Anecdotally, a lot of people seem to like saying the worst possible (offensive) things to Alexa and some people use it to sext. I don’t know if the latter was transmitted because messages are fair game or if because the user incorrectly tried to use the messaging feature. The only thing about this that really surprises me is that it isn’t outsourced to a cheaper labor supply.

I don’t have a Glassdoor account to confirm what this is saying but I think you’ll find at least circumstantial evidence here if you can view it. https://www.glassdoor.com/Reviews/Amazon-Data-Associate-Revi...

It's built into the app. It asks you to grade each response positively or negatively.