MondomuyoSiren is an app that plays a sound of the siren. It's too noisy, so please be careful. ("Mondomuyo" means "no question asked" in Japanese. ). If you ring the siren, you can call for help from people around you. Settings. Sound a siren immediately. Play a sound of a siren on starting app. It's too noisy, so malfunction. Set the volume of the siren.