Perfecting Operational Sound Quality at Ford

By Mike Mello


My first car was a ’76 Chevy Caprice Estate that reminded the driver to fasten his or her seatbelt by flashing an approximately 2×2-inch red warning light on the dash which simply read: “Fasten Safety Belts.” If their was ever a buzzer that accompanied this feature, it had died out by the time I made off with that $375.00 bargain.
No kidding, that wagon was just as reliable as the ’96 Tacoma I drive now, which shows me the red-colored seatbelt dash light upon startup. At this point, the seatbelt symbol is occasionally accompanied by a single-tone repeated 3-5 times, resonating from somewhere behind the dash pad.
About a month ago, I had the chance to travel to Dearborn and take part in a presentation at a Ford sound quality engineering lab. Other writers and myself didn’t just learn about noise vibration and harshness testing, we got to don the ear goggles and be part of a quick focus group-style sound test. For about 20 minutes, we listened to various samples of car sounds and voted which latch, electric motor, and revving engine sounds appealed to us.
Why test the sound of how a door shuts? It’s just one of those defining car characteristics that sticks in an owner’s mind. It’s a sign of perceived quality. Just think back to the cars you’ve owned and I bet there was at least one that had a distinctive door latch sound that just felt right.
The Ford sound quality engineers are way, way into perfecting the sounds that define their vehicles and the closing of a door is just one of the sounds engineered under the Operational Sound Quality group. I would have to nominate the door latch sound as one of the most important operational sounds that gets overlooked by the consumer which may just have the strongest subconscious connection to the driver. I mean, really – you hear this sound over and over again – it’s easy to see why the engineers might employ the use of polymer bumpers on the door latch’s catch and pawl in order to achieve the proper sound that’s not too harsh, but still feels solid and of high quality.
Like the old seatbelt alert described above, or the one that alerts you that your keys are in the ignition, Ford is developing a new family of refined tones that will be introduced on the ’09 Ford Flex. Instead of a single chime, the sound quality engineers have developed a multi-tonal chime which will resonate through the speakers, as opposed to being mounted in the dash or kick panels. Why? By playing the new chime through the speakers, you can drop the frequency and further refine the chime.
Although lots of people think of exhaust notes as being heard outside the car, the sound engineers are also concerned with how you hear the engine’s roar inside the cabin. You wouldn’t want your Jaguar XK to sound like the new Mustang Bullitt, right? Each car delivers its own refined flavor and the interior sound is just as important as that which we hear from the dual pipes.
Nearing the end of our sound quiz, I mistook the sampled sound of a Ford GT for that of a Mustang GT. How sad. I realized my inaccurate guess when the engineers played the Mustang GT’s signature exhaust note next, followed by that of the 2009 F-150. One of the special pieces of equipment used to get the interior sound just right on the Jaguar XK is a component they unofficially called the “bark” tube, pictured below. By bolting the bark tube to the dash panel, air pressure from the intake manifold is plumbed into a membrane that tunes the exact engine sound you hear while sitting in the driver’s seat.

After removing my headphones and checking out the results of our test, our group found that we had basically selected the kinds of sounds that Ford is building into its latest lineup. We even got to check out a Fusion sedan that had an older-style door latch installed on one side and the newer, refined latch on the other side. Based on this comparison, the newer door latch sound produced a tighter, less metallic sound.
Looking ahead, a member of our group asked about the possibility of drivers programming their own chimes and warning tones. When you think of personalizing ringtones, why not, right? While there was no up or down vote cast on this idea, perhaps custom car interior tones will become an option in a couple years. Wait – has anyone already done this? If you’ve hacked into your car’s computer and customized any of these sounds, please do let me know.
COPYRIGHT – All Rights Reserved

Author: Chris Haak

Chris is Autosavant's Managing Editor. He has a lifelong love of everything automotive, having grown up as the son of a car dealer. A married father of two sons, Chris is also in the process of indoctrinating them into the world of cars and trucks.

Share This Post On


  1. When electric ars become more widespread, will car makers “make up” an auditory soundtrack for people who crave the sound of a internal combustion engine? It interesting to think about.

  2. The engineers I was able to speak with seemed to think that they would not be developing an artificial engine sound for electric cars. I agree though, it’s definitely something worth exploring, even if it’s not a sound that mimics an internal combustion engine.

Submit a Comment

Your email address will not be published.