What is that sound?

Einzelganger7: I always play while listening to music but some minutes ago I was watching a recent replay I saved with volume at maximum level and noticed an odd ringing sound that happened twice during the match (you can listen to that here https://vimeo.com/626852977). It is kind of annoying so I guess I will keep playing while listening to music but I am intrigued, is it a normal sound added with the battle communications? If so, what does it indicate?