But sometimes, Bloomberg reports, a copy of the audio is sent to a human reviewer at one of several Amazon offices around the world.

The human listens to the audio clip, transcribes it, and adds annotations to help Amazon's algorithms get better.

“We take the security and privacy of our customers’ personal information seriously,” an Amazon spokesman said in a statement emailed to Bloomberg.

It's not hard to see why Amazon would want to have some audio clips reviewed by human beings.

There's probably no substitute for having a human being listen to clips and verify that the software is interpreting them correctly.

But Amazon could have been more explicit about the role of human reviewers.

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