New computer making a constant notification sound

[Pb1949]

My 2 day old desktop is continuously making a descending 3 note sound over and over. It sounds like a notification but I cannot find the source. The only way to stop it is to turn the speakers off

[WAWood]

@Pb1949 

Not only does Windows produce notifications, but applications do so, as well. 

If these are Windows-based, if you look down at the lower right corner of the task bar, you will see an icon that looks a lot like a monitor screen.  That is the notification area.  If you click that, it will open the Notifications panel.

If these are applications, we can't help as there are hundreds of those and they all work differently.