In The Future, Will All Cars Have Built-in Synthesizers?

In the future – will all cars have built-in synthesizers?

The LA Times reports that the new all-electric Nissan Leaf, above, has a built-in synthesizer – because it’s so quiet that the car would otherwise be dangerous to blind people:

Electric cars and hybrids offer the promise of a cleaner alternative to gasoline-only cars. They’ve also raised new concerns. At slow speeds, electric cars and hybrids make almost no noise. According to a recent study by the National Highway Traffic Safety Administration, pedestrians and bicyclists are hit twice as often by hybrids as by conventional cars at intersections, parking lots and other spots where cars normally slow down.

Developing the Leaf’s sound was a huge challenge for Tsuyoshi Kanuma’s team at Nissan’s labs in Atsugi, southwest of Tokyo. Make it too soft and people wouldn’t know that a car was approaching. Too loud and it might annoy the person behind the wheel or stir complaints from neighbors. Too strange and children and old people wouldn’t recognize it as a car.

“It got more complex as we looked into it,” Kanuma said.

For help, Kanuma turned to music theorists, movie sound-effects specialists, acoustics psychologists and transport officials.

Kanuma’s early experiments were with music. He met with a pipe organ expert in Germany and a music professor at Tokyo University of the Arts. He had his team compose songs but later dropped the idea.

“Colleagues in the U.S. told us it sounded like an ice cream truck,” he said.

Kanuma’s breakthrough came while analyzing traffic sound. Ambient noise can vary among cities. But Kanuma stumbled upon the common link: Noise generated by friction between a car’s tires and the road peaks at around 1 kilohertz.

Working with a Hollywood sound studio, Kanuma’s team mixed tones above and below 1 kilohertz. Tones at the low end of the spectrum, around 600 hertz, were easy for elderly pedestrians to pick out. Adding in higher tones of 2 kilohertz to 4 kilohertz would help the sound carry without it being too loud. That was something Kanuma heard about when studying how opera singers make themselves heard above an orchestra. “We called our sound ‘twin peaks,’ ” he said.

In late 2009, Kanuma sent a dozen sounds for testing to Vanderbilt University in Nashville. In an anti-echo chamber fitted with a ring of speakers, researchers asked subjects whether they could tell where the sounds were approaching from amid background noise. “It represents the complex listening task that blind pedestrians perform at a street corner,” said Daniel Ashmead, a professor who led the study.

At Western Michigan University, tests showed that the sounds were more audible than the engine of a gasoline-powered car. Kanuma’s team also polled experts at the Detroit Institute of Ophthalmology and met with child behavior specialists at the University of Idaho.

In early 2010, Kanuma flew to Detroit with a Leaf prototype and tested the sound at crosswalks and in parking lots. Officials from the National Federation of the Blind recommended changes. “The car’s sound started too abruptly,” Kanuma said. “They suggested giving the car an idling sound.”

You can hear examples of the Nissan Leaf sound design below.

Nissan Leaf Startup Sound

Nissan Leaf Forward Sound

Nissan Leaf Reverse Sound

Sound design challenges like electric cars raise lots of interesting possibilities and questions.

For example – it would be cool if you could load customized sounds for your car – much like you do with ringtones. But, there could be safety benefits to having cars sounding the same when they are doing things like turning or backing up.

Check out the examples above and let me know what you think of the future of sound design for cars!

10 thoughts on “In The Future, Will All Cars Have Built-in Synthesizers?

  1. Cool stuff.

    Reminds me of how metro stations in Japan each have their own individual jingle so passengers can audibly recognise where they are, plus the start and end of each jingle fades perfectly into the fall/rise of the engine's whine.

  2. I think they should make the cars sound like a one from a futuristic sci/fi film. From the examples it looks like that is the direction they are headed. I hope they are working with Skywalker Sound.

  3. Dude, if I were blind.. that backing up noise would freak me right the fuck out. From all the sounds I think the blind will get hit way more often because they'll be looking out for spaceships.

    It is a challenging problem though, and will give them credit for a well thought out solution. The sounds are well designed too.

  4. I think a better solution is to simply get rid of the electric cars 🙂

    Now, I know this is cynical but those cars are by far as good for the environment as people try to make you believe. There are many concerns which come with using electricity however those seem to get commonly ignored because electricity is "clean" energy after all.

    Apart from the obvious question "where does the energy come from" there is also the dire problem of storage. Batteries are extremely expensive and only last for so long; esp. when looking at the quite heavy charging/using cycle they need to go through. And considering that these batteries cannot be easily re-used they'll need to be recycled, which brings the matter of many chemicals being rendered unusable for the purpose of a battery.

    Personally I'd rather see a synth inside the car for my own pleasure than using one for the outside 😉

  5. Cars making spacedrone noises in the same key. Well, whatever, there are hardly any electric cars on the streets anyway.

  6. This bums me out, here's an opportunity to reduce noise pollution in cities, but instead we have to add more. I mean are there lots of jaywalking blind people or something? I just dont see that as a problem. Its kind of like those backing up beeps trucks have, they do nothing but irritate people for a half mile in every direction.

  7. "…by far as good" you say, and though you misspoke, you're right.

    The question of where the energy comes from is a good one, but electric vehicles are so much more efficient that even if the electricity was generated with coal, it creates less pollution — and this applies even to homebuilts using lead-acid batteries.

    And, even crude lead-acid conversions could offer more range than the average driver needs in a day.

    The future is electric. I say this not only because battery technology keeps moving forward, but because there are technologies that have been heavily suppressed for many decades — but cannot remain suppressed for much longer, thanks to our newfound connectivity.

    We will have small devices capable of generating more electricity than we'll know what to do with, seemingly out of nothing. Sure we will also be able to produce synthetic fuels from carbon dioxide, but in time those fuels would almost exclusively be consumed by classic vehicles, ones whose owners would not wish to have converted.

    I am not making this up. The technologies exist.

    As to artificial sound generation for electric vehicles, I do agree that it is probably a good idea for the short term — but the systems should be interactive, changeable. For one I wouldn't want my car to make the lame noises in that Leaf video on startup (yes you need an indication that the vehicle is ON, but no — please, not that).

    Note to automotive manufacturers: Hire Gary Numan, Ronald Jenkees, Daft Punk, the Crystal Method, Mark Mothersbaugh, MSTRKRFT, or someone similarly proficient to compose your vehicle sounds.


    Stay crunchy,


  8. My thoughts exactly. A chance to reduce noise pollution would be great. The next step is to reduce the noise pollution of all the litigation from the general public not looking both ways before crossing a street (maybe they should stop texting once in a while) and blaming it on anything else but their own inattention.

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