The teaching faces process is done through the Envision AI app. You can teach faces in the Feature Preferences on the Envision app. In the Envision app, take about 5-10 pictures in different angles of the person's face you want Envision to recognize. Save the images and wait a couple of seconds for Envision to crunch its brain. The faces you have taught Envision, will be spoken out when you scan the person's face.