{"id":1560,"date":"2026-05-04T11:48:08","date_gmt":"2026-05-04T15:48:08","guid":{"rendered":"https:\/\/www.elastomer.kuraray.com\/us\/?p=1560"},"modified":"2026-05-04T11:48:10","modified_gmt":"2026-05-04T15:48:10","slug":"noise-vibration-and-harshness","status":"publish","type":"post","link":"https:\/\/www.elastomer.kuraray.com\/us\/blog\/noise-vibration-and-harshness\/","title":{"rendered":"What is Noise, Vibration, and Harshness?"},"content":{"rendered":"\n
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What is Noise, Vibration, and Harshness?<\/h1>\n\n\n\n

Author<\/p>

Yoshihiro Morishita<\/a><\/p><\/div><\/div><\/div><\/div>\n\n\n\n

Noise, vibration, and harshness (often abbreviated NVH) refers to the measurement<\/strong> and modification<\/strong> of the noises and vibrations made by a machine. NVH is primarily focused on passenger vehicles<\/strong>, such as cars and trucks, where noise and vibration are key considerations for user comfort.<\/p>\n<\/div>\n\n\n\n

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Why does NVH matter?<\/h2>\n\n\n\n

Noise and vibration are prominent elements of a passenger\u2019s experience in a vehicle. NVH optimization allows automotive<\/strong><\/a> manufacturers to limit unwanted sounds and sensations (like loud roaring and jarring rumbling) while enhancing desirable ones (like the growl of a sports car or motorcycle). Electric vehicles, with different powertrains and lightweighting requirements, pose their own unique challenges.<\/p>\n\n\n\n

As a result, proper NVH management in a passenger vehicle is critical to enhance comfort and safety, improve perceived quality, and differentiate a brand from its competition.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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What is noise?<\/h2>\n\n\n\n

The sounds produced by a machine\u2019s operation are referred to as noise<\/strong>, an objective, physical quantity spanning audible frequencies that can be measured in Hertz (Hz), often with issues concentrated from tens of Hz into several kHz<\/strong> (typically from 20 to 5,000 Hz, and sometimes beyond). Noise is primarily carried to the passenger through the air (airborne<\/strong>).<\/p>\n<\/div>\n<\/div>\n\n\n\n

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What is vibration?<\/h2>\n\n\n\n

The mechanical oscillation felt throughout a machine during operation is called vibration<\/strong>, and is typically most impactful from a few Hz up to the low hundreds of Hz, in most cases from 1 to 200 Hz<\/strong>. Vibration is primarily carried to the passenger through the structure (structure-borne<\/strong>).<\/p>\n<\/div>\n<\/div>\n\n\n\n

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What is harshness?<\/h2>\n\n\n\n

Harshness<\/strong> is the subjective experience of both noise and vibration combined. It is often evaluated through user trials, but not all noises and vibrations are equally harsh to all users.<\/p>\n<\/div>\n\n\n\n

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Noise and vibration are measurable physical phenomena produced by a machine. Harshness is the user\u2019s subjective experience of noise and vibration.<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n
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Sources of NVH in cars<\/h2>\n\n\n\n

NVH sources in cars fall into one of three categories: aerodynamic, mechanical, and electrical.<\/p>\n\n\n\n