OODLE Journal
Get under the bonnet of the Oodle Journal; read about the dream journeys we’ve made possible and the technologies shaping our industry.
Five fake car sounds (to make the vehicle sound better)

Toy car wth toy person opening bonnet

We hate to break it to you but some of those really satisfying car sounds such as the purr of the engine or the wholesome clunk of the closing car door are manufactured – that is, the noise is not simply a by-product of their function but a purposefully engineered attempt to sound ‘good’. Below we explode some acoustic-based myths about our four-wheeled friends.  

The satisfying clunk of the car door

Around 15 years ago, car safety requirements meant extra bars had to be placed in the side doors. To compensate for the extra weight, they needed to make other parts of the car lighter including the catches and door mechanisms. However, this resulted in a very tinny sound when you closed one of the doors.

Picture of a car door on a vintage car

Trevor Cox, professor of acoustic engineering at the University of Salford told the BBC,

“What manufacturers realised is when you go to see a car in a showroom you don’t hear the engine first. What you hear is the sound of the door opening and the sound of the door closing. It’s a really important first impression sound.”

So, they set about artificially creating the satisfying clunk that had been lost by introducing dampeners into the door cavity to muffle the tinny effect. Engineers also altered the locking mechanism to create the original click we’ve become so accustomed to.

The Purr of the Engine

We hate to break it to all those vehicular audiophiles who love nothing better than to listen to the purr and roar of their favourite car engines, but they are not always real.

Many modern cars have become increasingly fuel efficient and therefore quieter. Worried that this would put off car lovers, many manufacturers have rigged up clever ways to boost or synthesise the sound.

Close up of car engine from a vintage car.

From BMW to Ford all reputable car manufacturers are at it. While some companies boost the actual sounds of the engine through special pipes, other manufacturers have taken it a step further. The BMW M5 for example, replicates the engine noise inside the car through thestereo system!

Click click goes the indicator

While you may think the clicking sound of the indicator is there to remind you to turn it off once you’ve done the necessary manoeuvre, it is in fact just a by-product of indicatorengineering. Essentially, it is the noise of the metal contacts and coiled spring inside the dashboard electrics which are activated to make indicator lights switch on and off.

Front wheel of a car at night time

And while modern cars no longer use this technology, they simulate the sound to match what the driver has come to expect when they turn the indicator on.

Pitch Perfect EVs

In the absence of combustion engines, electric cars are extremely quiet. In fact, they are dangerously quiet because people crossing the road tend to use their ears more than their eyes.

In response, Nissan has developed a singing car to alert pedestrians to the car’s presence at the same time as being sonically pleasant.

Called Canto (which means ‘I sing’ in Italian) it  sounds like a string quartet tuning up, getting higher as the car speeds up.

The fake non-noise

As well as creating fake noises, some car manufacturers are looking at how to synthetically cancel out real noises. Take Ford, for example, who has teamed up with Sony to cut out undesirable noises.

The Ford Mondeo Vignale with Active Noise Control, uses three small microphones embedded around the driver and passenger seats of the car to cancel out background noise while driving by counteracting the noise with opposing sound-waves from the audio system in the vehicle.

Like noise-cancelling headphones, the system works best for low frequencies, such as the noise of the engine and the sound of the road, so you’re still able to hear important noises such as emergency sirens.