Beeping sound when in Windows Messenger App on video session

Every time I use a Messenger video chat using the Windows 10 Messenger App, there is a constant beeping noise for the entire session. It is a series of 6 beeps with the first being loudest, then decreasing in volume to the last one, then it repeats again. It sounds like a heart beat monitor or a submarine. When I first open Messenger, I do not hear the sound. As soon as I connect to someone, it begins. But after ending the session, the beeping continues until I close the App. Any help would be appreciated. Driving me nuts!!!