Vehicle horn Several languages have either borrowed or transcribed the name into their lexicons. In Japanese, the word refers to car horns in general, and in verb form () refers to sounding the horn. This is also true in languages such as French (), Italian (), Dutch (), Russian (), Polish (), Spanish (), Romanian (), Czech (), Turkish (), Indonesian (), and Korean (). In countries applying the Vienna Convention on Road Traffic, usage of audible warnings is limited, and allowed only in two cases: Vehicle horn A horn is a sound-making device that can be equipped to motor vehicles, buses,
Sound from ultrasound to have sounds audible to only one person, or that which a group wants to listen to. The navigation instructions for example are only interesting for the driver in a car, not for the passengers. Another possibility are future applications for true stereo sound, where one ear does not hear what the other is hearing. Directional audio train signaling may be accomplished through the use of an ultrasonic beam which will warn of the approach of a train while avoiding the nuisance of loud train signals on surrounding homes and businesses. This technology was originally developed by the US Navy