Play different sound when notification is urgent

src/DBus.vala

@@ -138,7 +138,15 @@ public class Notifications.Server : Object {
                     }
                 }
                 if (app_settings.get_boolean ("sounds")) {
-                    send_sound (hints);
+                    switch (notification.priority) {
+                        case GLib.NotificationPriority.HIGH:
+                        case GLib.NotificationPriority.URGENT:
+                            send_sound (hints, "dialog-urgent");
+                            break;
+                        default:
+                            send_sound (hints);
+                            break;
+                    }
                 }
             }
         }