In this scenario, the app will change which sounds are played with the toast.

Toasts can use audio clips from a set of Windows sounds (including "silent").

Press one of the buttons below to hear an example of that sound:

Since notifications are just XML, you can create them in many different ways. Above, the NotificationsExtensions library is used. You can also create notifications with strings:
silent default mail

When you display a toast, its XML will appear here.