Why bisq uses 2-4% CPU for audiodg.exe all time?

Hi,
I noticed that bisq uses 2-4% CPU for audiodg.exe (“Windows Graphisolierung für Audiogeräte”) all the time. Quitting bisq the CPU for audiodg goes to 0% again.
Is that necessary? Can’t bisq only address the program if necessary? bisq doesn’t make sound all the time.
Regards
Detlef