Google wrote in the report (pdf) on the development of his self-propelled cars. The cars will include horns like a car unexpectedly traveling on the road or swinging from his job.
The company has created software that can recognize when the car horn may help to alert other drivers to their presence. In the test phase, the horn sounded only inside the Google car. The driver then got to the ability to know whether the signal was due, so that the engineering team was able to adapt its software.
Google has therefore developed software horn by sounding a signal initially only in the car. For example, the test drivers could indicate whether the warning was in place or not and that feedback could learn the system. Eventually honks the car now as a car just leaving its lane or unexpected comes away from a driveway. There are even different types of horns built, short and long, matching the situation.
Also the fact that Google’s car is completely electric, is a danger. To inform pedestrians and cyclists to the presence of the car, Google says several ‘engine noises have tested. From the sound a killer makes the typical hem of electrical appliances, eventually opted for a “unique voice” whose volume – similar to cars with internal combustion engines – increases during acceleration. The sound should be friendly and futuristic, Google said.