When watching the live stream in the Apple Home app on a connected iOS/iPadOS/macOS device, you can communicate with someone you see in the video stream using the Home app and the microphone and speaker on the doorbell.

1. To start talking, toggle the microphone button in the live stream for the camera in the Home app. You'll be able to listen to the person in front of the doorbell while you are talking, just like in a normal phone call.2
2. When you are done, un-toggle the microphone button in the live stream for the camera in the Home app.