Designers Turn To Nature To Create Warning Sounds For Next-Generation EVs
The once lauded silence that heralded the introduction of EV’s could soon be replaced with a customised soundtrack inspired by nature, according to an industry expert.
Coby Duggan, Volvo NZ general manager, says with international legislation requiring new electric-powered vehicles to make some sort of noise while driving at city speeds from next year, automotive designers are turning to the natural environment for inspiration.
Research has found near-silent EVs are up to twice as likely to have a collision with a pedestrian, primarily as a result of the difficulty in hearing them approaching.
“As we transition from internal combustion to battery-powered vehicles, the absence of engine noise presents a potential for risk road users - particularly those with vision impairments.
“Pedestrians and cyclists often rely on their ability to hear a vehicle as it approaches and drivers will also adapt their driving to engine sounds such as over-revving, allowing them to keep their eyes focused on the road.
“European legislation will see the Acoustic Vehicle Alerting System (AVAS) become mandatory on new vehicles from mid next year to help ensure the safety of road users as we migrate to an electric power source.
“A key element of acclimatising first time EV owners to their new vehicles will see the introduction of a range of ambient sound effects to the vehicle’s interior and exterior features,” he says.
Duggan says there is a trend towards the use of more natural and sustainable materials in the manufacture of vehicles and designers are also looking to enhance the driving experience with a range of sounds that are sourced from nature.
He says the addition of curated ambient sounds in a vehicle will become an intrinsic part of the driving experience for the next generation of EV owners. For example, Volvo designers have previously researched the sound of hundreds of spruce and fir tree twigs snapping as the foundation for a distinctive turning signal sound which is now found in many of their vehicles.
“Sound engineers snapped and recorded over 300 sticks in a Swedish forest before the right base sound was found for the source audio file.
“They then layered the sound and adjusted its pitch up and down to create the noise before slowing the timing between the clicks to a more calming rate of about 150 beats per minute to create the final sound that Volvo drivers hear when turning or changing lanes,” he says.
Duggan says in keeping with their sustainable ethos, all the twigs that were snapped were from dead trees found on the forest floor.
A natural sound source will also be used for the AVAS system on the automaker's upcoming EVs.
The XC40 Recharge and other electrified models from the carmaker will use a vocal sample as the base for the noise the vehicle makes when standing still. The sample is adjusted and layered and will resemble a slowly pulsing choral ensemble that's intended to be calming.
The sound is subtle and designed to be heard from about six feet away. While the vehicle is moving forward, a slight hum is created. It gets louder as the vehicle speeds up and cuts off at about 29 km/h.
Duggan says the noises are created from the desire to reduce the sound pollution of vehicles as much as possible while still emitting audio that warns pedestrians, cyclists, and other drivers of the approach of a vehicle.
He says New Zealand does not currently have any regulations covering the mandatory use of AVAS.