You may be wondering, “What is NVH in automotive?” NVH stands for noise, vibration, and harshness – three factors that have a significant impact on the driver experience.
Understanding each component helps engineers create vehicles that are comfortable, quiet, and enjoyable to drive.
- Noise: In the context of automotive NVH, noise specifically refers to unwanted noise in the vehicle cabin. This may be engine noise, road noise, or the rattle or hum of a poorly installed component, among countless others. While some noise while driving is virtually unavoidable, excess noise can make for an uncomfortable driving experience.
- Vibration: At different speeds, or frequencies, automotive components may begin to oscillate, or vibrate. A driver may be able to feel these vibrations via the seat, the steering wheel, the pedals, and even the floor. Some vibrations are absorbed by rubber components, created via automotive die-cutting or extrusion, but some sources of vibration can be more challenging to address.
- Harshness: Harshness generally means the discomfort associated with experiencing sound and vibration. Harshness is the most subjective variable of automotive NVH, since every driver will have a different threshold in terms of how much noise or vibration in the cabin bothers them.
The Importance of NVH in Automotive
Automotive NVH is important for several reasons, all of which can play an important role in the commercial success of a given vehicle.
As mentioned, automotive NVH directly impacts driver comfort and the driving experience. Many people prioritize a test drive when shopping for a new vehicle, so they can experience the car’s “feel” for themselves. Optimizing automotive NVH is key to providing the experience a driver is looking for.
On a related note, automotive NVH is important in terms of perceived quality. If a vehicle has a loud cabin, with excess rumbling, rattling, or vibration, an experienced driver may perceive the vehicle as lower quality. On the other hand, given the number of luxury vehicles that emphasize a quiet cabin in their marketing, a peaceful driving experience is often associated with quality.
However, there is more to automotive NVH than driver experience. Unexpected noises and vibrations are often the first sign of a potential maintenance or repair issue. When normal automotive NVH is kept to a minimum, drivers can be more sensitive to unusual noises and rattles and get their car to the shop.
Common Sources of Automotive NVH
Some common sources of automotive NVH can be loosely grouped into three categories: mechanical, electrical, and aerodynamic. Mechanical sources of automotive NVH include things like brake friction, the contact patch between the tire and the road, and general engine noise. Electrical sources of automotive NVH include driver alerts. Aerodynamic sources of NVH include factors such as heating and air conditioning systems and wind against the body of the vehicle. While there are many solutions to consider when addressing these challenges, common strategies include automotive die-cutting and other custom rubber components to secure systems and parts in place.
The surrounding environment also contributes to automotive NVH. The construction of the vehicle plays a role in how much ambient noise, such as traffic, penetrates the cabin, which also affects driver experience.
It’s worth noting that sources of automotive NVH differ between internal combustion engine (ICE) vehicles and electric vehicles (EV). For example, the tremendous weight of EV batteries puts considerable pressure on EV tires, which in turn generates more road noise. Many tire manufacturers are working to fine-tune their EV tires to alleviate this issue.
Conducting NVH Performance Testing
Automotive NVH can be assessed in a controlled laboratory environment, so engineers can isolate and address potential issues in the early stages of development and manufacturing.
NVH performance testing is often conducted in a soundproof chamber, so test engineers can isolate sounds and more easily pinpoint the source. Engineers may use a wide range of different tools to detect and quantify noises and vibrations, such as sound quality and power measurement, octave band analyzers, FFT spectrum analyzers, and more.
Harshness, however, must be evaluated subjectively. Often, experienced test drivers will provide subjective feedback after driving the vehicle.
Benefits of Reducing NVH Issues in Cars
The greatest benefit for reducing NVH in cars is optimization of the driver experience. NVH reduction creates a more comfortable environment for drivers and passengers, which is desirable for many consumers. Additionally, reduced NVH can minimize operator fatigue, which is incredibly valuable for long-haul drivers and other professionals who may spend many hours in a car.
Reducing NVH can have other benefits as well. In some contexts, noise levels are regulated by governing authorities. Reducing NVH may make it easier for OEMs to comply with regulations. Additionally, reducing NVH can improve the reliability and lifespan of the vehicle by controlling rattling components and other issues that may lead to maintenance problems.
Start Reducing NVH Issues with Universal Polymer & Polymer
Universal Polymer & Rubber (UP&R) is proud to help automotive manufacturers cut down on NVH by starting at the component level. Our automotive die-cutting, extrusion, and molding experts can manufacture tubing, gaskets, and other components to your exact specifications, so you can ensure a close fit that eliminates rattling and muffles vibration. Our services are highly customizable, so we can work closely with you to develop precision rubber components that support your automotive NVH reduction goals. From the early stages of product design to airtight manufacturing practices with exceptional quality control, you can count on UP&R to be your partner as you strive to minimize NVH and create an excellent driver experience.
To learn more about our automotive die-cutting, extrusion, and molding services for custom rubber parts, contact us.