The listening mode on the device is triggered when the wake-word “OK Webex” is detected. The wake-word toggles on the listening mode. Otherwise the listening mode is off. The microphone is only streaming audio from the device while the Webex Assistant pane is active and the “Listening” symbol is displayed on the screen.
The voice data is collected on the device and then streamed to the speech recognition service. The data isn’t saved anywhere, and only used while processing it. When the voice data is streamed to the speech recognition service, it’s encrypted and sent over HTTPS.
For more information on Webex Assistant for Devices and security, you can read the security white paper.