Phone Vibration Sound App. You can adjust whether your apps display app icon badges or not. If an app is set to “sounds” without “banners,” it will play a notification sound without showing you any visible notifications.
Go to settings> sound and vibration (sound/ volume), check vibration is turned on or off; The sound of a whistle. There is no doubt, this app will become one of your favorite.
Apps can have invisible notifications that vibrate your phone or play your notification sound.
Open your phone's settings app. You can adjust whether your apps display app icon badges or not. Adaptive sound only works on your pixel phone. For example a referee flute.