FEATURE1 February 2012

Vroom for manoeuvre


Car makers are starting to introduce artificial engine sounds to their electric vehicles for pedestrian safety. But what sort of sounds do drivers want? Robert Bain speaks to the researchers who are trying to find out.

Electric vehicles promise a future of lower emissions, better efficiency and less noise. But cars that can move almost silently also introduce a new road safety problem.

Pedestrians who have had the experience of walking out in front of an apparently stationary hybrid car only to watch it roll toward them without a sound know how unnerving it can be. A 2009 report by the US Department of Transportation found that hybrids were twice as likely as normal cars to be involved in collisions with pedestrians and cyclists when manoeuvring at low speeds (when the engine is at its quietest). For blind and partially sighted people they can be particularly dangerous.

Back in the early days of motoring, drivers of “road locomotives” were required to have someone walk ahead of them waving a red flag to warn people they were coming. It soon became clear that this safety measure was excessive, and since then the loud and recognisable sound of a combustion engine has been relied on as one of the signs warning people of a car approaching. Engine noise, it turned out, was not just a side effect but a safety feature.

Makers of hybrid cars including Nissan, Chevrolet and Toyota are now beginning to introduce artificial warning sounds, and some countries including the US and Japan have already brought in rules requiring manufacturers to do so. This involves fitting speakers to the front (and sometimes back) of cars to produce the sound we’ve learned to expect. It can even change in pitch and volume to indicate speed and gear changes, like a real engine.

For car makers, adding sounds to electric vehicles represents a challenge and an opportunity. How do you create a sound that is loud enough but not too loud, compliant with any relevant regulations, and hopefully adds to rather than detracts from the driving experience?

Sensory signals
Harman, which makes audio and entertainment systems for vehicles, wanted to find answers to these questions. The company has worked with Lotus Engineering to develop the Halosonic system for cars, which combines sound synthesis and noise cancellation technologies. Kay Robinson, Harman’s marketing manager for European customers, says manufacturers had a wide range of ideas about how their electric cars should sound, “from those who wanted them to mimic existing cars precisely, to those who wanted something completely different”. To bring the customer in on this conversation Harman approached research agency MMR.

MMR’s approach to sensory research is all about what they call ‘conceptualisations’ – the ideas conjured up by sensory stimuli. Think of a taster describing a glass of red wine as robust, gutsy or elegant. None of these is a literal description of the wine’s physical properties – they are hints at the concepts that were triggered in the taster’s mind when they drank it.

According to MMR, the sensory experience of a product – its taste, texture, sound or anything else – needs to match the brand in the associations it elicits. Consumers might like the smell of your shampoo, but if they feel it is not in harmony with your brand then the message gets muddled and the product is less likely to be successful.

For automotive manufacturers this means cars don’t just need to sound good, they need to sound right.

More than six hundred people took part in MMR’s survey, split into three cells: family car, 4x4 and sports car owners. Each cell was divided into two groups with some respondents asked to think about their existing cars and others asked to imagine an electric equivalent.

Pippa Bailey, research manager at MMR, said: “We wanted to understand how different categories of car users would conceptually profile their current type of vehicle, versus if that vehicle was a hybrid electric vehicle. We then wanted to get them to profile the different sounds.”

The respondents associated standard petrol and diesel cars with words like confident, powerful and trustworthy, while electric cars were linked to words like trendy, adventurous and quirky

In an online survey respondents were asked to quickly drag words (from a lexicon developed by MMR and Harman) on to a target to indicate how closely they associated them with a type of car. To profile the sounds respondents undertook a similar task after watching a 30-second video of a car accelerating with different types of engine sound overlayed.

The MMR team were then able to compare the profiles of the three categories of car, the current and hybrid versions, and the different sounds. “This was a way of trying to understand the conceptualisations and associations that people have without having to ask a lot of direct questions,” said Bailey.

Music to my ears
The respondents associated standard petrol and diesel cars with words like confident, powerful and trustworthy, while electric cars were linked to words like trendy, adventurous and quirky. As for the sounds, the noise of a V6 engine threw up words like aggressive, masculine and powerful.

Manufacturers will have to ensure that any sound supports the emotional and functional associations of the particular car and brand, and Harman will be using the findings in its discussions with them.

As for people’s stated preferences, women and family car drivers said they wanted quieter sounds, like the whirring of a hairdryer or leaf blower, while 4x4 and sports car drivers were more keen for electric cars to sound like their petrol or diesel equivalents. This might mean introducing gear shift sounds even though hybrid cars don’t use conventional gears.

Clearly there are opportunities for car brands to differentiate themselves, or to let drivers customise the sound their cars make. Some manufacturers are even looking at licensing engine sounds to make sure nobody else can use the same one.

The road ahead
In the future, who knows what cars might sound like. Harman is working with pop music producer Steve Levine on artificial sounds to replace engine noises, while still reflecting speed and gear shifts. One day people might be able to download their engine noise like a ringtone.

“There’s a big opportunity to own some sounds,” said Bailey. “Companies can develop sounds which fit their brand and what they’re trying to communicate, to provide that sensory signature of their brand. For a vehicle manufacturer, every touchpoint should reinforce what the brand is communicating, and the sound of the engine is critical to that.”

David Howlett, strategic planning director at MMR, said: “Sound has not been a key area of marketing activity for auto manufacturers, but all of a sudden with hybrid vehicles becoming more of a standard option, they’ve got something as part of the marketing mix that previously they didn’t have.”

Although some manufacturers already pay close attention to the sound of a car’s engine, or of the doors closing, Howlett hopes they will begin to approach this sort of thing more rigorously. “We’re hoping that other auto manufacturers might take note and realise that simply asking people in the form of focus groups or interviews what one car door sounds like compared to another might not be the way to go.”