The Masters Who Gave Life to Nissan ARIYA #07

Engineering Monster will present interviews with the engineers involved in the development of Nissan ARIYA, a car that symbolizes "Nissan Intelligent Mobility" and is the culmination of Nissan's technology, and will provide a glimpse into the engineers' commitment to this car, the behind-the-scenes development of innovative technology, and "Nissan DNA" that lives on in Nissan ARIYA. We will deliver Nissan DNA that lives in "Nissan ARIYA" as original content.

In this issue, Toshio Enomoto, who oversees the sound and vibration performance of Nissan vehicles, tells us what kind of quietness is appropriate for a premium crossover EV.

The quietness of “Nissan ARIYA” is comparable to that of a residential environment.

"It's like a living room".
This is a term used to describe the comfort of a car interior, such as sofa-like comfortable seats and a space that does not feel cramped, etc. I describe Nissan ARIYA's high level of quietness as "like a living room". The three main sources of noise that enter the cabin during driving are the engine, tires, and wind. Even at speeds in the 50-60 km/h range, which is the speed range of ordinary roads, the sound is as loud as that of a factory.

Have you ever experienced anything like this? You were listening to music comfortably while driving on the highway, but when you stopped at a service area, you were surprised at how loud the music was and panicked and turned down the volume. The human brain is smart, and when we are in a noisy environment, our brain naturally stops listening to noise. At this time, it also shuts out the sound of music, so we tend to turn up the volume. 

Nissan ARIYA was developed with the goal of achieving a sound vibration performance equivalent to that of a living environment, and we were able to achieve that. That is why I describe it as "as quiet as a living room".

"Nissan Leaf" has been a turning point in terms of sound vibration performance.

The frequency of sound produced by an engine is very different from that of a motor. When a V6 engine is running at 3000 RPM, the sound is around 150 Hz, which is to the left of the middle of the keyboard in a piano. However, when the motor starts running, the sound quickly reaches the right end of the keyboard - several kilohertz. If you heard this at the same volume level as the engine, it would be painful to the ears.

Nissan had been producing electric cars in small quantities before the debut of Nissan LEAF. However, at that time, running a car on a motor was still a difficult task in itself, and honestly, no attention was paid to sound vibration performance. When we developed the mass-produced EV "Nissan LEAF", our goal was to create a completely different value system from engines, not only in driving performance but also in quietness. I am proud to say that we were able to set a global standard for how quiet electric vehicles can be.

Nissan LEAF was a turning point in my thinking about sound.
Cars with engines have a long history, so there is a "rule" that the balance of noise sources (engine, tires, and wind) should be about the right level when determining sound vibration performance. The development of an electric vehicle without an engine required a fundamental and drastic change in our thinking. In developing Nissan ARIYA, we felt it was our mission to achieve the highest level of quietness in the absence of "laws".

There is no one-size-fits-all technology for sound vibration performance. 

Nissan has been working on sound control from a very early stage. Active noise control, which blasts sound in the opposite phase to the noise entering the vehicle, was released in the early 1990s. Active control engine mounts, which incorporate electromagnets in the engine mount and use their power to cancel sound and vibration, were implemented in the late 1990s.

Nissan ARIYA is equipped with many innovative technologies, such as e-4ORCE and ProPilot 2.0. However, the sound and vibration performance is rather traditional technology to enhance the performance. In the area of quietness, there is no technology that can "sweep all noise under the rug", but rather a series of steady efforts.

This is no different for the premium EV "Nissan ARIYA".
The knowledge we have gained through years of car manufacturing and our 10 years of experience making "Nissan LEAF". This is the essence of Nissan ARIYA's sound and vibration performance.

When there is no intention to accelerate, Nissan ARIYA's sound is muffled to the point where you can't even tell the motor is running. When the driver presses down hard on the accelerator pedal, the motor sound can be heard as information to the driver, to the extent that it does not disturb them. The sound of tires and wind are also isolated in various ways.

I hope customer take Nissan ARIYA out for a long drive and enjoy the conversation to the fullest.

The quietness of a car is similar to the lining of a suit. Few people choose a suit because they are in love with the lining, but if the lining does not do a good job, the suit will be ruined. The same goes for quietness. I believe that giving customers a car that is quiet enough to match its price and brand image is a promise between Nissan and its customers.

When Nissan ARIYA arrives in your possession, I hope you will take it out for a long drive with full occupancy. You should be able to enjoy conversations with your neighbors as well as those in the front and rear seats in a normal voice. Above all, you will be surprised to find that even on long drives, the level of fatigue caused by noise is completely different from that of ordinary cars.

The article is from its original version released on 10 February 2021.