Why Car Component Sounds are Purposely Designed

Cars are astoundingly engineered machines – dependent on thousands and thousands of parts precisely machined to fit together (hopefully) like a hand in a good glove. The precision of many of these parts is essential for safety on the roads: if brakes don’t work, if steering isn’t accurate, and if tyres aren’t dependable, the consequences can be awful.

Some other car parts are instead precisely engineered for comfort and ease: heated seats, infotainment systems, parking sensors, suspension, steering wheel leather, wood veneer panels, and so on are beautiful touches that we could very well do without but which add a lot to the experience of driving.

But you may be surprised to hear that there’s a whole category of car design that fits somewhere in between the safety and comfort zones – one dedicated solely to engineering the sounds that cars and car components make.

Engineered sounds for EVs

The most obvious and most contemporary element of car sound design is with the recent explosion in EV production. One of the first things drivers noticed with electric motor cars was the surprising lack of noise – specifically within the vehicle.

Cars make a lot of noise just driving around, you can usually hear any car approaching due to the noise of the tyres and the air moving over the car’s body. But the danger here is that, because EVs are still quite new and reasonably uncommon, people aren’t accustomed to the sound of one approaching. Taking the rumble of engines out of the equation means people aren’t listening out for the engine sound of approaching cars.

On the inside, the sound of an engine inside the car gives you a lot of feedback – of how healthy the engine sounds and, importantly, of how fast you’re likely to be driving. In high end family estate cars, for example, with large 2+ litre engines, the quietness of the engine often means that it’s easy to accidentally build up to a speed exceeding legal limits. The driver should be observing other road users, of course, but on quieter roads, it’s easy to forget how fast your car can go (though that defence won’t stand up in court).

This short documentary by the BBC explores the surprising niche of EV sound design – both for external sounds as well as those inside the car. The general scientific consensus is that reducing external noise pollution is a huge positive for public health as well as for wildlife.

A key intention was to make car noises that don’t imitate combustion engines – they are, after all, a technology that EV manufacturers are purposely trying to get away from.

What other car noises are actively designed?

The noise of an engine is a reasonably obvious one in the case of EVs because there isn’t a noise from the “engine”. But you may be surprised to find that a real variety of other components are also purposely designed to sound a certain way.

Things like car doors locking, the sound of a handle opening, the sound of a button being pressed in, the sound of the indicators, the headlight button being engaged, a reverse sensor, a seat belt locking in, and (almost) countless other things are all purposely designed to make you feel a certain way.

Why are car sounds purposely designed?

Take a moment to imagine a high quality car of any make or model. The driver gets into their car and closes the door – how does that door sound? Is it a higher-pitch “clang” or a low frequency “thud”? When the door locks, how does that sound? Do the parking sensors make a noise that distracts the driver from parking?

All these sounds give an indication of quality construction. But what’s considered a marker of quality construction actually varies culturally. Some cultures, like Japan as an example, consider higher-frequency sounds as better markers of quality for the “cleanness” of the sound while others, like in Western Europe, tend consider higher frequency sounds as “thin” and therefore favour lower frequencies for their association with “solidity”.

But purposely designing sounds for components isn’t just for the sake of giving an impression of quality – a component giving you feedback that it is being engaged lets you more quickly understand that it’s working as it’s supposed to. If, for example, the car made no noise when the doors locked, you’d likely have to check and re-check every time you locked the doors that they had in fact locked. If the indicators made no noise, you’d likely forget that they were on. This physical and sonic feedback that we get from everyday things (what specialists call “haptics”) is actually crucial to helping us navigate the world.

Component giving you the wrong feedback?

If a component is giving you trouble, trust the experts at your local Kwik Fit centre to get it back to where it should be in no time.