Electric cars make very little noise when travelling at slow speeds. This might sound like a good trait – finally, a break from the constant traffic noise that’s been blighting our cities! But their low noise levels have also caused significant safety concerns. It’s lead to the development of sound for electric cars and the new law from the European Union.
The electric vehicle industry has seen massive growth in recent years. This is set to continue as petrol and diesel cars are phased out. While the uptake of electric vehicles is predominantly a very positive move, research suggests that electric cars are 40% more likely to hit pedestrians than conventional vehicles.
Without warning sounds, a hybrid car running in electric mode is only audible 3.4 metres away. In comparison, a traditional combustion engine vehicle is audible at 11 metres. When travelling at speeds below 20 km per hour, electric cars are extremely quiet. This lack of noise is particularly dangerous for the visually impaired and blind, children, the elderly, and runners and cyclists.
New laws for electric cars
As of July 1st 2019, all new electric and hybrid cars in the EU will have to emit sound by law when travelling at low speeds. These legal warning sounds are called Acoustic Vehicle Alerting Systems or AVAS. Specifically, electric cars must emit a continuous noise of at least 56 decibels any time the vehicle is moving below 20 km per hour. (Thankfully its volume can’t exceed that of a traditional combustion engine, so this won’t be making our roads any noisier!) Once the vehicle is travelling faster than 20 km per hour, tire and wind noise will make enough noise to warn pedestrians.
This new also law stipulates that the electric car sound must communicate certain behaviours to pedestrians, like acceleration and deceleration. It also sets out detailed parameters about the sound – such as specific octave bands and frequencies. Generally, the noise will be comparable to a vehicle with a combustion engine.
Other countries and organisations have also implemented similar new electric car laws. The USA, Japan, China and the United Nations all have their own take on it. USA’s legislation initially looked set to enforce sounds with a similar frequency to ambulance sirens, but thankfully this was rejected. These laws have minor differences from region to region, which car manufacturers will need to be aware of. Mercedes’ electric car sound, for example, differs slightly in the US compared to the EU, Japan and China as result.
How can electric car manufacturers ensure their sounds create the a safest environment for pedestrians? Chris Hanson-Abbott of Brigade Electronics has advised the UN on sonic safety standards. “The object is to have warnings which are audible but which are not the least bit environmentally disturbing”, he says. Hanson-Abbott explained that the benefit of white noise is its pleasant ambience. Crucially, its directional source is instantly recognisable. By contrast, it is harder to judge the source of tonal sounds, which bounce off hard surfaces.
Branding electric car sound
The ability to introduce custom electric car sound (albeit within the confounds of the new laws) has also raised the question of branding. This situation certainly brings a unique opportunity to electric cars and the new law gives just enough lenience for brand differentiation. For some automobile companies, motor sound is synonymous with the brand itself. Harley Davidsson once attempted to trademark the sound of their engine.
It remains to be heard how manufacturers will use audio branding in tandem with the new safety legislation to differentiation their cars. In 2013, technology company Semcon proposed an ambitious Sonic Movement. It highlighted the opportunity for intelligent, responsive automobile sound. The project included vehicle noise that adjusts to its surrounding environment, to ensure the noise is audible but never a nuisance. It also proposed sound that synchronises with surrounding vehicles. Imagine, for example, a tribe of harmonious BMW’s pulling up to a set of traffic lights.
While branding on this level may be ruled out by the specifics of the new AVAS laws, automobile brands are working to make the most of this sonic opportunity. BMW, for example, is currently working with composer Hans Zimmer to create their sound.
With such important sonic decisions to be made, these new laws certainly give automobile brands added incentive to have a core audio identity in place. Our core recommended services include strategic auditing and research, sonic guidelines, and a library of core audio assets.