Take a walk down any busy street and the noise can hit like a speaker accidentally left on full volume. The growls of engines accelerating when the traffic light turns green, motorbikes vying for position in the traffic, buses whizzing past and the odd rev-head all compete to be heard.
The sound generated by the internal combustion engine has shaped urban life for a century but that is gradually going to change: by 2050, 90% of cars in Australia will be electric.
Australia is developing noise standards for electric cars that may follow similar rules set by the UN or US, industry experts say. But what exactly an electric car, and ultimately our cities, will sound like is under the creative control of carmakers. And each is doing something different.
When an electric car travels above 30km/h, it sounds much the same as a petrol-driven vehicle, as the noise is emitted from the tyres vibrating against the road rather than the engine, says Lex Brown, an urban sounds expert at Griffith University.
But below that speed, it becomes barely audible.
This spells danger for pedestrians, particularly people who are vision impaired. One survey by Vision Australia and Monash University found 35% of respondents who were blind or had low vision had experienced a collision or near-collision with a hybrid or electric car.
So, if noise is to be added artificially, what should an EV sound like?
‘Like something out of Star Wars’
Ashley Sanders, the technical director at the Federal Chamber of Automotive Industries, says Australia is likely to mirror Europe’s UN regulation or follow similar rules to the US. Both require electric cars to emit a sound – amplified by exterior speakers – that changes in frequency according to speed.
But while carmakers say safety is the main objective of creating an EV noise, it’s also an opportunity to shed the confines of engine sounds and come up with a whole new sonic character. What each manufacturer thinks that sound should be varies wildly.
Some are employing the most accomplished musical minds in the world to create it. BMW hired Hans Zimmer to help score their electric car sound, the inspiration for one model supposedly starting with a chord from a Beatles song. Jaguar has employed the US electronic musician Richard Devine, and Volkswagen hired Leslie Mándoki, a Hungarian-German drummer and music producer.
When the musician and sound designer Danielle Venne, of Made Music Studio, was asked to lead the design on the acceleration sound of the Nissan Leaf, she experimented with layering samples of woodwind instruments, flutes, clarinets and synthesisers.
“It ends up feeling like something out of Star Wars,” Venne says.
Fiat was the first to sample a human voice in the sound of its electric car, which has been overlaid with a chord from Nino Rota’s soundtrack for the 1973 movie Amarcord – the end result sounds as though you are sitting at a theatre and the curtain has just been raised on a show.
Sound designers at Renault took inspiration from sci-fi films, creating a sound for the Zoe model that has been compared to being chased by a heavenly choir of angels.
General Motors sampled a didgeridoo for its Cadillac Lyriq, while the base of the sound design for one Audi model started with some plastic tubes that in-house sound designer Rudolph Halbmeir found in his garden.
“I took one of these tubes … and I bumped on it with my hand and it made a boom and I thought, well this sounds interesting,” Halbmeir says. He then placed the tube against an electric fan and recorded it.
Some carmakers, such as Hyundai, are experimenting with recreating the sound of the petrol car.
“You can rev it … and it even vibrates as well,” says Tim Rodgers, product development manager at Hyundai Australia. “So it feels like an internal combustion engine, for lack of a better term, but it’s an EV.”
Also being considered is whether drivers should be able to choose the sound their cars make. Yuri Suzuki, a sound designer who has consulted for a number of carmakers, imagines drivers being able to select from a template instruments that have the same pitch, so as not to create a nuisance.
But some initiatives have proved controversial. Tesla’s Boombox feature allowed drivers to play preset or custom sounds, resulting in choices such as fart noises or bleating goats that obscured its standard pedestrian alert system. The US National Highway Traffic Safety Administration found it violated safety standards and 579,000 cars were recalled as a result. Elon Musk blamed the recall on the “fun police”.
The US has since banned customisable sounds but it is not yet clear whether Australia will follow. The infrastructure department says no decisions have yet been made, and draft regulation will be released for consultation next year.
Tyranny of dissonance
The thought of disparate sounds overlaying one another as more and more electric cars take to the streets has left some concerned it will lead to a new kind of urban cacophony.
Chris Edwards, director of government relations and advocacy at Vision Australia, which has campaigned for electric car noise standards, says he isn’t worried by carmakers choosing different sounds, as long as they clearly identify the source of the noise as a vehicle, and don’t aggravate the broader community.
But sound designer Connor Moore, who has worked for a number of different car brands, says making a signature sound for each brand could create an environment that is dissonant and out of tune.
“All of these brands are living in their own isolation and creating their own individual sounds, most of which are tonal,” he says. “But they’re not taking into consideration the harmonious aspect … what the soundscape will really sound like when all of those sounds come together.”
Moore thinks regulation on car sounds should go a step further, and may well do so in the next five to 10 years.
“We could have in regulation that these things can’t be so tonal. To me that’s an easy fix. So it becomes less of a branded experience and more of a functional experience.”
Suzuki, who shares Moore’s concerns, says a way should be found to make the sound of electric cars harmonise.
“In an ideal world we’d be calculating the sound design based on psychoacoustic research,” he says, referring to the science of how humans perceive sound.
Regardless of the sound choice, experts agree urban life will be quieter once electric cars are the predominant mode of transport.
“The amount of sound electric vehicles will make will pale in comparison to internal combustion engines,” Venne says. “We’re talking about a scenario where you might be in a quiet environment with no other sounds but electric cars going under 30km/h. Put me there, please. That sounds like a delightful environment to live in.”
Edwards, who navigates the outside world with a seeing eye dog, says a quieter urban soundscape may amplify sounds that can’t compete with raucous engines.
“When you’re blind, you are appreciating the world through your other senses – whether that’s sound or feel or smell,” he says. “If I walk through a park and hear the birds, and have that peace rather than hearing a nearby busy road, it’s going to be a much more pleasant environment.”
