When buying a car, the sales consultant usually mentions the mute effect of the car, and most car advertisements also publicize that "XX car has undergone dozens of nhv upgrades, which can bring a quiet ride feeling".

NVH可以说是一个汽车术语，它是“Noise Vibration Harshness”的缩写，即噪声、振动、声振粗糙度。

NVH can be said to be an automobile professional term, which is the abbreviation of "noise vibration harshness", that is, noise, vibration and sound vibration roughness.

之所以在工程领域总是将震动与噪声综合在一起讲，是因为声音总是伴随着震动而来。声音是由物体震动而产生的声波，并通过媒介（固体、液体或气体等，比如钢铁、水和空气）传播。而人耳能听得到的声波范围在20Hz-20kHz，低于或者高于这个范围的声波，人耳都是无法识别出来的。

The reason why vibration and noise are always combined in the engineering field is that sound always comes with vibration. Sound is a sound wave generated by the vibration of an object and transmitted through a medium (solid, liquid or gas, such as steel, water and air). The range of sound waves that can be heard by the human ear is 20Hz-20KHz. The human ear cannot recognize the sound waves lower or higher than this range.

优美的旋律音乐会让人心情舒畅，相反的人要是长期在吵杂的噪音中会带来很多负面影响。医学家研究发现，噪音会严重影响人们的睡眠质量，并会导致头晕、头痛、、多梦、记忆力减退、注意力不集中等神经衰弱症状和恶心、欲吐、胃痛、腹胀、食欲呆滞等消化道症状。它还有害于人的心血管系统，我国对城市噪音与居民健康的调查表明，环境噪音每上升一分贝, 高血压发病率就增加3%。

The beautiful melody concert makes people feel comfortable. On the contrary, if people are in the noisy noise for a long time, it will bring a lot of negative effects. Medical experts have found that noise will seriously affect people's sleep quality, and lead to neurasthenia symptoms such as dizziness, headache, insomnia, dreaminess, memory loss and inattention, as well as gastrointestinal symptoms such as nausea, vomiting, stomach pain, abdominal distension and dull appetite. It also has a harmful effect on the cardiovascular system of people. Our survey of city noise and residents' health shows that the incidence rate of hypertension increases by 3% per environmental noise.

所以，足够安静的驾乘环境才会带来更舒适的乘坐体验。也因此，如今不论是高档豪华轿车还是普通家用轿车，都在强调车内噪音大小。但是，车内真是越安静越好吗？

Therefore, a sufficiently quiet driving environment will bring a more comfortable riding experience. Therefore, nowadays, both high-end luxury cars and ordinary family cars are emphasizing the noise level in the car. But is it true that the quieter the car, the better?

其实，在很多汽车工程师看来并非如此。

In fact, many automotive engineers do not think so.

，人们不能试图彻底噪声和振动。

First of all, people try to eliminate noise and vibration completely.

我们知道，汽车的动力源于发动机，并更终传递到车轮上，轮胎克服路面摩擦从而推动汽车前进。

We know that the power of the car comes from the engine and is finally transmitted to the wheels. The tires overcome the friction on the road and push the car forward.

所以，一辆汽车的振动来源就有很多，不仅有发动机、变速箱等运转产生的振动，也有轮胎与路面摩擦、经过坑洼路面时产生的振动，而这些振动都将产生噪音。此外，还有风噪、零部件之间的碰撞、空调出风口、电路的电流声等，都是一辆车的噪音来源。

Therefore, there are many sources of vibration of a car, not only the vibration generated by the operation of the engine and gearbox, but also the vibration generated by the friction between the tire and the road and when passing through the pothole Road, and these vibrations will produce noise. In addition, there are wind noise, collision between parts, air conditioning outlets, current sound of circuits, etc., which are all the noise sources of a car.

其次，驾驶员所需要的很多反馈都来源于噪音和振动。

Secondly, much of the feedback that drivers need comes from noise and vibration.

在开车的过程中，驾驶员需要收集各种路况反馈信息，这些信息的主要形式无外乎声音，振动，视觉信息三类。而彻底消音就意味着驾驶员听不到其他车的鸣笛声、发动机或变速箱产生的异响声、轮胎亏气造成的摩擦声、轮胎与地面接触产生的冲击声。而路面振动又会通过转向系统回馈到驾驶员的手上，驾驶员除了会感受到这些振动，它们产生的声波也会传递到驾驶员的耳朵里。

In the process of driving, drivers need to collect various road condition feedback information. The main forms of this information are sound, vibration and visual information. Complete silencing means that the driver cannot hear the whistle of other vehicles, the abnormal sound generated by the engine or gearbox, the friction sound caused by tire air loss, and the impact sound caused by tire contact with the ground. The road vibration will be fed back to the driver's hand through the steering system. In addition to feeling these vibrations, the sound waves generated by them will also be transmitted to the driver's ears.

同时，路感对驾驶员也很重要。假如振动彻底被抑制，方向盘没有把路面信息反馈给驾驶员，汽车的驾驶品质也就无从谈起了。

At the same time, the road feel is also very important to the driver. If the vibration is completely suppressed and the steering wheel does not feed back the road information to the driver, the driving quality of the car will be out of the question.

此外，噪声振动品质过分的好，风噪胎噪抑制的过分的好，会让人丧失对车速的感觉。如果你开车到200km/h以上时，还像你坐在家里沙发一样安静，会让人在充分安逸的状态下开车，此时很可能就不认为自己在超速，而时间久了还会让人犯困，这就是一种极度危险的状态了。

In addition, if the quality of noise and vibration is too good, and the suppression of wind noise and tire noise is too good, people will lose the feeling of speed. If you drive more than 200km / h and are as quiet as you are sitting on the sofa at home, it will make people drive in a fully comfortable state. At this time, you may not think you are speeding, and it will make people sleepy after a long time. This is an extremely dangerous state.

，太过分的安静也会让人感到压抑。

Finally, too much silence can also make people feel depressed.

俗话说“沉默是金”，但如果人待在过分安静的环境里，却会让人无法忍受。

As the saying goes, "silence is golden", but if people stay in an excessively quiet environment, it will be unbearable.

美国一间“消音室”的建造者奥菲尔德说：“在安静的环境下，耳朵会逐渐适应。屋子里越安静，耳朵听到的东西越多。你会听到心脏的跳动，甚可以听到你的肺和胃发出咕噜声。在消音室，你自己变成了噪音。”他说，在这种静室中，很容易令人迷失方向，时间久了还会令人产生幻觉。

"In a quiet environment, the ear will gradually adapt. The quieter the room is, the more things the ear hears. You will hear the beating of your heart and even the grunting of your lungs and stomach. In the anechoic room, you become noise." He said that in this kind of quiet room, it is easy to lose direction and hallucinate over time.