AI assistants -- bots like Alexa and Siri that answer your questions, set your alarms and order goods online for you -- are among the most buzzed about consumer product features of the last several years.

Apple, Amazon, Google and Samsung have each made their own, pre-installing them on phones, tablets, smart speakers and home appliances. While numbers can be hard to come by, Amazon announced in January, 2019 that they'd sold over 100 million smart speakers since launching its first Alexa services in 2014.

These companies have marketed their assistants' use of artificial intelligence and machine learning technology, saying that helps them answer questions creatively and improve the more they're used.

However, it wasn't until contractors began going to the press that we learned to the role humans play in the background.