Mercedes-Benz B-Class Electric Drive, front three-quarter view

As regulations encourage wider adoption of electric cars and more OEMs get into their electric-car stride, we're getting a better idea of what the synthetic tones we'll be hearing on our electrified streets. Not only will it be unlike anything we've ever heard, it could get pretty raucous according to a Bloomberg article that surveys the sound engineers creating the notes sung by electric cars.

Daimler has 250 people in its powertrain acoustics department who are most used to finessing the din of an internal combustion engine. Lately they've been on the other side, creating tones like the "sonorous purring" for the Smart ForTwo Electric Drive, the "huskier" whine of the SLS AMG Electric Drive and the sci-fi movie whirring of the B-Class Electric Drive. The Nissan Leaf makes its own sound, the Tesla Model S makes no manufactured sound, and the Renault Zoë offers three sounds. Neither Volkswagen nor BMW, however, will install sounds on their electric offerings unless required.

Authorities around the world are preparing regulations that will force electric cars to produce some kind of warning note to pedestrians and cyclists - an expert with a German organization for the visually impaired actually spoke for all pedestrians and street users not in cars when he said, putting it midly, "What is important for us is that we don't get killed in traffic." Automakers are therefore looking for ways to create notes that resonate with the driver and that can make their offering as distinct as the water-cooled six cylinder in a Porsche 911, and owners are already thinking about what kinds of tunes they want their car to emit. For a sample, you can check out the three notes offered by the Zoë in the video below.