Since the dawn of the automotive industry, car manufacturers have worked tirelessly to combat noise issues directly related to the engine, exhaust system, wind, and tires. Having finally developed technologies to keep the car cabin’s airtight and sound-free, you might say they’ve gone a little too far. In fact, muffling road and engine sounds so efficiently can all but stifle the raw driving experience.
Drivers of performance vehicles in particular began voicing their desire for a return to the thrills produced by raw engine growls, with carmakers responding around 10 years ago by working on ways to meet this emerging consumer demand. A variety of sound-enhancing features have since been launched by some of the biggest car manufacturers, receiving a mixed response from drivers.
To learn more about engine sound enhancement, let’s take a closer look at this ever-evolving technology, and some notable versions of it.
Volkswagen Takes a First Stab at Engine Noise Enhancement
Volkswagen was one of the first carmakers to play around with the idea of sound enhancement, adding a sound actuator (known as a “Soundaktor”) at the base of the bulkhead windscreen to supply computer-generated noise under certain driving modes. The audio file could be played directly from under the car’s hood, via a speaker located near the engine’s throttle housing.
Many car owners would disable the device, feeling let down by the notion of “fake” motor sounds. However, VW would remain undeterred with its concept, going on to improve the technology and adding its Soundaktor to its current GTI, GLI, and Beetle Turbo models. It also uses the sound tech on many models in the performance lineup of its Audi vehicles.
Designers with Auto Careers Develop the Sound Pipe and Sound Symposer
For a sportier sound, some Toyota and Subaru models, as well as the Ford Mustang, use simple sound enhancers that pipe noise from the car’s intake manifold to its cabin. While those with auto careers recognize that this very basic technology does its job, some car owners have found the constant sound to be intrusive, especially when their vehicle is revved up to anywhere above 4,000 rpm.
To solve the problem, Ford came up with a Sound Symposer system, which also runs a pipe from the intake manifold to the dash’s rear. An electronically-controlled flap added to it makes the difference, and the gear, driver’s speed, and acceleration each play a role in its opening and closing. Better yet, it produces added noise only when expected. The system can be found in today’s Focus ST and Fiesta ST models.
BMW’s Active Sound Technology Receives Mixed Reviews From Those With Auto Careers
BMW started work on sound enhancement with its M5 model, using a recording of its exterior motor and playing the sample based on rpm and engine load through the vehicle’s stereo system. Not only does this technology give the driver a more visceral driving experience, but it also serves the practical function of assisting the driver to shift by ear. Those training in automotive industry practices will also be interested to learn that this technology minimizes the risk of bumping the car’s rev limiter during full use of the rpm range.
Not everyone is a fan of this reproduction of engine noise, however, with BMW using negative feedback to make improvements to the technology. On its current M3 and M4 models, the sound coming through the speakers is in fact an amplification of the natural engine noise, as opposed to the synthesized sounds on its M5. Drivers of the M5 who wish to switch off the reproduced engine sounds can do so with the simple removal of a fuse.
How Is Sound Enhancement Used in Electric Vehicles?
Used to add a reassuring roar to the otherwise eerie silence of the electric vehicle, car manufacturers continue to evolve the use of sound enhancement on EVs, where drivers may be somewhat more forgiving of the use of artificial noise.
Check out the noises used for the BMW i4 EV in this clip:
As an example of some of the experimental musings taking place in the EV market, BMW teamed up earlier this year with famed musical composer Hans Zimmer to produce the “soundtrack” to its latest concept i4 car. The world-renowned composer created “Limen” for the vehicle, a unique soundscape that ranges between a core sound to a sport mode sound. Door opening and start-up sounds are also included.
Car enhancement has caused its fair share of controversy in the automotive industry, but car manufacturers are likely to continue to work with the technology as they look to strike the ultimate balance—dissipating unwanted road and engine noise while providing just the right level of natural sound to keep the driver more engaged behind the wheel.
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