MASTERMINDS BEHIND SONIC INNOVATION DISCUSS ULTIMATE ENGINE SOUND

SEOUL, Sept. 6, 2023 — In the luxury car market, certain elements are just non-negotiable. One is tranquility. 


Creating an ambiance of unparalleled serenity is key to realizing the ultimate driving experience. Flagship models were traditionally synonymous with hushed interiors and opulent surroundings, but times are changing, and so are people’s perceptions. 


Genesis is redefining its flagship model, the G90, by introducing an unprecedented level of driving pleasure in the luxury car sector. At the heart of this transformation lies ESEV (Engine Sound by Engine Vibration) technology, which transmutes engine vibrations into customized virtual engine sounds, enhancing the driving experience to seamlessly match the driver’s preferences. 


Exclusively developed by Hyundai Motor Company engineers, ESEV, making its debut on the G90, faithfully captures the engine’s nuanced responses, crafting an auditory symphony that synchronizes with each wheel turn and pedal press. 


In a recent interview, researchers at the company’s eP Acoustics & Vibration Research Lab discussed how they came up with the technology and what it means for the future of driving. 


The following are excerpts from that conversation. 


What’s the difference between ESEV and ASD?  

Dongchul Lee (senior research engineer): While ASD [Acoustic Sound Design] generates virtual engine sounds independently of the vehicle’s physical characteristics, ESEV goes a step further, taking into account the engine’s physical characteristics, like vibrations, to create the driving sounds that customers desire. To incorporate these physical characteristics, we developed new sensors that measure real-time engine power response vibrations and a communication module for signal processing. Signal components required for acceleration driving sounds are extracted from the vibrations recorded by these sensors, which allows our unique algorithms to create sounds that perfectly align with driving performance. 

 

How did you get to develop ESEV technology?  

Insoo Jung (research fellow): Some drivers pointed out that the ASD does not perfectly sync with their perceived driving performance, especially during accelerations or gear shifts, as the technology doesn't account for the engine’s physical characteristics. That's why we started developing ESEV technology. In general, driving performance is determined by how the engine responds to the combustion process. ESEV is a unique sound control technology that leverages real-time engine vibrations. When the driver accelerates, it creates virtual sounds synchronized with vehicle speed and gear shifts, in effect delivering a sporty driving experience. 
 

Why are sound and vibrations significant in cars?  

Insoo Jung (research fellow): The competitiveness of a car often comes down to various factors such as performance, functionality, design and NVH [noise, vibration and harshness]. Among these, noise and vibration are considered particularly crucial as they can both create problems for the driver and the surrounding environment if neglected. For this reason, the ability to control the noise and vibration contributes significantly to a model’s competitiveness. Here at the eP Acoustics & Vibration Research Lab, we research technology to reduce noise and vibration in automobile powertrain systems. We strive to minimize noise and vibration coming from automobiles while enhancing driving pleasure through the development of driving sounds based on the physical characteristics of powertrain systems.  
 

While developing ESEV, how did you manage to effectively eliminate the sense of incongruence that drivers might feel with virtual engine sounds? 

Dongchul Lee (senior research engineer): Humans have incredibly sensitive hearing, capable of detecting even the slightest changes in sound within moments. When people drive, they perceive their surroundings through all their senses, including changes in sound and vision, as well as vibrations felt through their seats. When developing ESEV, our focus was to eliminate the sense of incongruence arising from the time delay between what drivers experience in their surroundings and the sounds they hear. Humans are known to recognize a sound delay as short as 0.03 seconds, or 30 milliseconds. Therefore, the control loop time of the ESEV control algorithm was optimized to 0.023 seconds, or 23.3 milliseconds, so that drivers don't feel any incongruence in the sound.

 

Why was the G90 chosen to be the first model to incorporate ESEV technology? 

Jinsol Jeong (research engineer): We wanted to provide Genesis G90 buyers with new experiences by outfitting the flagship model with the luxurious engine sound it deserves. We considered ESEV to be technology that suits luxury brands like Genesis because it responds faster than ASD, thus resulting in more natural acceleration sounds, while also enhancing the emotional quality. Also, this technology is the first of its kind in the world, so we wanted to make a powerful first impression by featuring it in the most luxurious model the company has ever assembled. 
 

Were there any difficulties while developing ESEV? 

Jaemin Jin (senior research engineer):  Our biggest concern was durability. No matter how good a function is, it must always be durable. To ensure durability, we repurposed knock sensors originally used in engines as vibration sensors. We then had to verify the vibration sensor signals to stably harness vibration signals in a previously unused frequency range. It was also crucial to adopt a communication method and arrange the wiring to reliably transmit vibration signals from the engine located at the front end of the vehicle to the interior audio control unit. After discussing with relevant teams, we managed to increase durability on all these aspects.

 

Sound design for the G90 must have been a tough task. How did the sound tuning process go? 

Boyong Kim (senior research engineer): The G90 isn't just the flagship model of Genesis. It's the embodiment of the brand's identity. To reflect these characteristics in the sound, we first needed to establish sound quality goals. After assessing and analyzing driving sounds from competing models of different brands, we noticed one thing in common: they all exuded a sporty vibe. The question was, should we also apply such a sporty sound to the G90? Our answer was no. We chose to differentiate ourselves. This led us to create a sound that's not only luxurious and sophisticated but also sporty and enjoyable at the same time. 
 

According to your customer research prior to the development of ESEV, what sounds do Genesis customers desire? 

Boyong Kim (senior research engineer): When developing ESEV, the key was to understand the sound characteristics consumers desired the most. Everyone has different tastes, so it was pertinent to identify customer needs. It turned out G90 customers favored a gentle sound, as many had chauffeurs. But then there was another group of G90 customers who personally drove the vehicles, prompting us to introduce engine sound technology features that make driving more exciting. Given that the G90 is Genesis' flagship sedan, we tried to design a sound that met customer preferences while staying true to the distinctive identity of the brand. Therefore, we decided to pursue the identity of Genesis through a calmer, quieter sound, while at the same time improving the pleasure of driving through a sporty yet sophisticated noise.

 

What are your team’s thoughts on the future of virtual sound technologies? How do you anticipate ESEV technology will be received by customers? 

Dongchul Lee (senior research engineer): Sound is not just something everyone loves, but also an important element that affects our behavior and emotions in various ways. This is why virtual sound technology is attracting lots of attention, unlike in the past when the focus was firmly on making cars quieter. We are now at a critical phase in our transition from internal combustion engine noise to the virtual sounds of electric vehicles. At a time when internal combustion engines and electric vehicles coexist along with the advancement of sound control technology through ESEV, we hope that the acceleration performance and cohesive sound of internal combustion engines will be recognized as details that enhance the joy of driving.