Electric buses in London have an odd problem. They are too quiet, which will require them to play an artificial noise.
From next year, some of electric buses in London will play artificial noise while traveling at low speeds, and the specific sound that has been created for them is an ambient treat for the ears. The noise was created by Zelig Sound, a recording studio in London, which has been working with Transport for London on the audio over the past year.
The sound is being introduced in response to a law in the EU that says all electric vehicles will need to produce artificial noise while traveling at low speeds. If you can’t hear a vehicle, then you are not as aware of its presence, and research suggests pedestrians are more likely to be hit by electric or hybrid cars as a result.
There is actually a law in the European Union, which the U.K. may soon leave, that requires electric vehicles to emit sounds when they are moving slowly. This is because of results of a research that show that silent vehicles can lead to pedestrian accidents, as people are usually less aware of vehicles that don’t make sounds. According to this law, all EU vehicles moving slower than 12 miles per hour must emit a sound that is at least 56 decibels.
When the bus is idling, it will make one type of sound, which sounds almost like a beat that an electronic music artist would use. Then, when the vehicle moves, it will add to this sound another three beats, which will indicate motion.
According to TheVerge.