What is low frequency noise and what is the harm of low frequency noise to people

Noise pollution. In recent years, among the complaints received by the environmental protection department every year, the complaints that the elevator noise detection standard but are considered to affect normal life account for about 35% of the noise complaints.

In the face of increasingly serious low-frequency noise pollution.

In the past, China's cities focused more attention on environmental pollution to control the pollution of water, gas and garbage, and often ignored sound pollution. Nowadays, more and more people are recognizing that noise is also harmful to human health and is a cause of disease.

What is low-frequency noise?

Low-frequency noise, the frequency is read in Hz.

Low-frequency noise refers to sounds with frequencies below 500 Hz (octave). In the range of the human ear, it is low frequency from 20Hz to 500Hz, that is, the irregular sound produced by vibrating 20 to 500 times in one second is called low-frequency noise.

GIF As early as the early 90s of the last century, low-frequency noise has quietly begun to affect people's lives.

The elevator in the high-rise building of the community is open in the entertainment place of the residential area.

The heavy low-metal sound system and the transformers and water pumps that were moved into the residential buildings became the "main culprits" for the low-frequency noise.

An environmental acoustic expert at the Fujian Provincial Environmental Monitoring Center Station said, "The same 70 decibel sound, 100 Hz and 1000 Hz frequencies will not be the same as the sound sensed by the human ear." Natural frequencies of organs in the human body.

Basically, in the low-frequency and ultra-low-frequency ranges, it is easy to resonate with low-frequency sounds, so people will be annoyed and feel uncomfortable. ”

However, the current domestic acoustic environment quality standards.

Its monitoring method is only for the detection of high-frequency noise, and there is no way to complain about low-frequency noise caused by transformers, elevators, air conditioners and "subwoofers" installed in the building. However, due to the lack of support for law enforcement and punishment standards, the environmental protection department is also powerless to control the pollution of low-frequency noise.

The propagation route of low-frequency noise.

Low-frequency noise is mainly divided into the following according to the propagation route:

Structural sound, airborne sound and standing waves.

Structural sound transmission refers to the elevator host installed in the building.

Transformers, water pumps, and air-conditioning hosts transmit low-frequency vibration sound waves to each household through the basic structure beams and load-bearing beams of the residential building.

Airborne sound refers to the direct transmission of low-frequency noise through the air to the households in the community.

Standing wave refers to the amplitude of low-frequency noise in the belly of the wave after multiple reflections during propagation.

The strongest, the most harmful to human health.

The frequency is read in Hz, and low-frequency noise refers to the sound with a frequency below 200 Hz (octave), and the sound frequency range of low-frequency noise in China is set at 20 200Hz, which has a more obvious impact on the human body, mainly in the frequency range of 3-50Hz.

In the range of the human ear, it is 20Hz-200Hz is low-frequency, that is, it vibrates 20 to 200 times in one second to make irregular sound, which is called low-frequency noise. The frequency at 500Hz 2kHz is the medium frequency, while the high frequency type is 2kHz 16kHz

Low-frequency noise refers to sounds with frequencies below 200 Hz (octave). There are five main types of low-frequency noise sources in residential areas: elevators, transformers, water pumps in high-rise buildings, air conditioners (including cooling towers) and traffic noise.

The sound that ordinary people can hear is between 20Hz and 20000Hz, below 20Hz is infrasound, and above 20000Hz is ultrasound.

Low-frequency noise is different from high-frequency noise, which can quickly attenuate with distance or obstacles, such as the point source of high-frequency noise, which can drop by 6 decibels every 10 meters. The low-frequency noise, on the other hand, decreases very slowly, and the sound waves are long, allowing it to easily pass through obstacles, run long distances, and penetrate walls and into the human ear. Vibration, low-frequency noise and ordinary noise all have the same property, they are all vibration waves, a way of energy propagation.

Low-frequency noise: Sound with frequencies between 20 Hz and 200 Hz.

Low-frequency noise can cause a sense of oppression on the human body, which has a great impact on sleep and health, and may lead to neurasthenia, depression, etc., especially in the elderly. If it weren't for the coherent long-term stay in that environment, it wouldn't be a big problem

Generally, people with psychological problems and poor mental state have lower mental immunity and will be more affected. Just don't have a psychological effect.

Not hearing the instructions is minor and not a big problem. But if you feel pressured in your room, irritable, or unwell, then you are still affected. There are some specific groups of people who are more obvious.

For example, when outdoors or when doors and windows are opened, the low-frequency noise part of the outdoor noise component is covered by other medium-high frequency noise and is not felt, but when the doors and windows are closed, the medium-high frequency noise will be soundproofed by the doors and windows and the low-frequency noise will be more obvious, so it is usually easier to feel the interference of low-frequency noise in the dead of night or when it is quieter.

Low-frequency noise is transmitted through structures, so it is easy to resonate with people's senses. Generally speaking, people have a relatively low tolerance for low-frequency noise. Under normal circumstances, 30 to 35 decibels is acceptable to the average person, and some people will feel uncomfortable above 35 decibels.

The natural frequencies of organs in the human body are basically in the low-frequency and ultra-low-frequency range, and it is easy to resonate with low-frequency sounds, so people will be troubled and feel uncomfortable. In addition, when low-frequency sound travels in the air, the air molecules vibrate less, the friction is relatively slow, and the energy consumption is less, so it travels farther, has strong permeability, and can easily pass through obstacles such as walls and glass windows.

There are generally three methods to control low-frequency noise: controlling the noise source, protecting the propagated and cutting off the propagation route. It is possible to use one of them alone, but in general, it is best to use all three methods together.

For example, when installing soundproof windows or using double or multi-glazed windows, when choosing household items, try to use soft materials, such as soft beds, soft sofas and soft walls, these are all ways to protect the person being disseminated. In addition, it can be actively controlled from the source, such as spraying water-based damping coatings on elevator cars and substations.

Difference Between Low Frequency Noise and High Frequency Noise:

First, the frequency range is different.

Low-frequency noise: Sound with a dominant frequency lower than 300Hz.

High-frequency noise: the main frequency is higher than 800Hz.

Second, the harm is different.

Low-frequency noise: More harmful than high-frequency noise.

High-frequency noise: less harmful than low-frequency noise.

3. The attenuation speed is different for the same distance.

Low-frequency noise: Slow attenuation.

High-frequency noise: fast attenuation.

Noise is a type of sound that causes people to be irritable, unable to calm down, or too loud and harmful to human health.

From the perspective of environmental protection, all sounds that hinder people's normal rest, study and work, as well as sounds that interfere with the sounds that people want to listen to, are classified as noise.

From a physical point of view, noise is the sound produced when the emitter vibrates irregularly.

The noise in the residential room should not exceed 50 decibels during the day and 45 decibels at night. Generally, when the noise is about 30 decibels, it will not affect normal life and rest, and when it reaches more than 50 decibels, it will be difficult to fall asleep, 10 to 20 decibels is almost invisible, 20 to 40 decibels is like whispering, 40 to 60 decibels is the standard of ordinary indoor conversation, and 60 to 70 decibels will damage nerves.

Hello, I am helping you to inquire about the relevant information and will reply to you immediately. Low-frequency noise refers to the sound with a frequency below 200 Hz (octave), and the sound frequency range of low-frequency noise in China is set at 20 200Hz, of which the frequency that has a more obvious impact on the human body is mainly in the frequency range of 3-50Hz. 

How many decibels of audio affect the bedroom.

The noise in the interior of the residential room should not exceed 50 decibels during the day and below 45 decibels at night. Generally, when the noise is about 30 decibels, it will not affect normal life and rest, and when it reaches more than 50 decibels, it will be difficult to fall asleep, 10 to 20 decibels is almost invisible, 20 to 40 decibels is like whispering, 40 to 60 decibels is the standard of ordinary indoor conversation, and 60 to 70 decibels will damage nerves.

Is low-frequency noise also the standard?

Is low-frequency noise also the standard?

The building is generated by the transformer.

Yes, dear.

1. Ordinary people's speech, walking and general humming are low-frequency noise.

2. Low-frequency noise is not harmful to people's physical and mental health under normal circumstances, and in many cases it is also conducive to improving work efficiency.

3. High-frequency noise mainly comes from industrial machines (such as looms, lathes, air compressors, air picks, blowers, etc.), modern vehicles (such as cars, trains, motorcycles, tractors, airplanes, etc.), loudspeakers, construction sites, shopping malls, sports and entertainment venues, etc. These high-intensity noises harm people's organisms, make people feel tired, produce negative emotions, and even cause diseases.

Frequency is read in Hz, and low-frequency noise refers to sounds with frequencies below 200 Hz (octave). The sound frequency range of low-frequency noise in China is set at 20 200Hz, of which the frequency with a more obvious impact on the human body is mainly the frequency range of 3-50Hz. In the range of the human ear, it is 20Hz-200Hz is low-frequency, that is, the irregular sound produced by vibrating 20 to 200 times in one second is called low-frequency noise.

The frequency at 500Hz 2kHz is the medium frequency, while the high frequency is 2kHz 16kHz.

The main noise frequency is mostly below 500Hz, which is called low-frequency noise. The main noise component is above 1000Hz, which is called high-frequency noise. The main frequency component of the noise is in the range of 500 1000Hz, which is called intermediate frequency noise.