If you have more than one Nucleus device, you can use the Broadcast All feature to send real-time audio from one Nucleus to all your others. The transmission is one-way, and only includes audio; nothing will be sent back from the receiving devices.
To send a broadcast message to all your devices, simply tap the button on the Broadcast All banner, located on the Home screen:
The banner will update to show that you're broadcasting, and provide a Stop button. Tap it to stop broadcasting.
Receiving devices will see this screen, indicating which device is broadcasting. It also allows them to adjust the volume and to dismiss the broadcast message.
Disabling Broadcast All
If you don't wish for a device to be able to send a broadcast, or you just want to hide the Broadcast All banner, you can do so in Settings > Device Settings.