Notifications in 46 and beyond
Quoting: Notifications in 46 and beyond – GNOME Shell & Mutter —
GNOME Shell can’t play notification sounds in all cases, depending on the API the app is using (see below). Apps not primarily targeting GNOME Shell directly tend to play sounds themselves because they can’t rely on the system always doing it (it’s an optional feature of the XDG Notification API which different desktops handle differently). This works, but it’s messy for app developers because it’s hard to test and they have to implement a fallback sound played by the app. From a user perspective it’s annoying that you can’t always tell where sounds are coming from because they’re not necessarily tied to a notification bubble. There’s also no central place to manage the notification behavior and it doesn’t respect Do Not Disturb.