Using Technology to Reduce Noise, Help Life "Silence" (Field Report)

(Original Title: Multiple Regions Innovate Measures to Promote Noise Pollution Prevention and Control Using Technology to Reduce Noise and Help Create a Quiet Life (Visit))

Neighborhood noise, construction site noise, traffic sounds… In daily life, some noise pollution is close at hand and may harm the interests of the people.

The newly enacted Ecological and Environmental Code has specific provisions for noise pollution prevention and control, responding to the urgent public desire for a “quiet life.” In recent years, many regions have actively used modern technology to innovate noise management methods, continuously improving the scientificity and effectiveness of noise pollution prevention and control, ensuring residents’ environmental rights at their doorsteps.

Preventing and Controlling Social Noise —

Neighborhoods Have a “Noise Map”

“Ding ding!” At 10 p.m., Zheng Jiajia, Party Secretary of Jiaxing Community in Liangjiang New Area, Chongqing, received a notification on her phone: “Noise levels exceeding standards detected online, please verify and handle on-site.” Zheng immediately coordinated with grid members and headed to Jiaxing Community.

It turned out that at the entrance of a supermarket inside the Lihe Garden community, some residents were sitting and chatting loudly, triggering a noise alarm. “It’s so late, everyone, keep your voices down so as not to disturb neighbors’ rest.” Hearing the advice, the chatting crowd immediately lowered their voices, and the Lihe Garden community returned to peace.

“This is an affordable housing community with prominent issues like poultry feeding and vehicle noise, which have become difficult community management problems,” Zheng said. Due to noise issues, Lihe Garden had experienced many neighborhood conflicts.

How to create a peaceful living environment? The answer begins with a “Noise Map.”

At the Ecology and Environment Bureau of Liangjiang New Area, a large screen displays a “Noise Map” showing real-time environmental sound levels in various neighborhoods. This is the Liangjiang New Area Smart Community Noise Monitoring Cloud Platform. On this “Noise Map,” several red flickers indicate areas where noise levels have exceeded daytime normal decibel levels. “The ‘Noise Map’ relies on GIS geographic information systems and IoT monitoring networks to collect noise data in real time and visualize it, automatically generating heat maps of sound levels and noise complaint distribution maps,” explained a relevant official from the Ecology and Environment Bureau. Through an intelligent early warning module, when noise exceeds preset thresholds, the system can accurately capture high noise sources, record sound, and automatically send alerts to community staff and grid members.

Today, many neighborhoods in Chongqing are equipped with noise monitoring devices, encouraging residents to consciously maintain a quiet environment. “I didn’t realize that talking loudly in the community could affect others before. Now we all consciously lower our voices in public areas,” said Mr. Guo, a resident of Lihe Garden.

To further reduce noise, Yinzhu Community has laid noise-reducing pavement, which, compared to traditional asphalt, has smaller particles that better reduce passing noise; Chunsantai Community’s new energy supercharging stations are fitted with soundproof covers; newly installed supercharging equipment uses low-noise, fully liquid-cooled advanced technology… In Liangjiang New Area, technological measures effectively lower everyday noise.

Since 2023, the Ministry of Ecology and Environment has promoted the construction of quiet communities nationwide. Currently, over 3,200 quiet communities have been established in China.

Preventing and Controlling Construction Noise —

Covering Construction Sites with Air Membranes

Recently, in Hongjialou Street, Licheng District, Jinan City, Shandong Province, a giant “white pillow” at the construction site of the urban renewal project “Honglou 1905” attracted public attention.

“This device is called an air-supported foundation pit membrane. It’s about 50 meters high, over 100 meters wide, covering roughly the size of 2.5 football fields. We use it to enclose the construction site,” said project leader Wang Luren.

Why cover construction sites with an air membrane? “Mainly for noise reduction and dust control,” Wang explained. The project is located in the core commercial district of Licheng District, surrounded by residential communities and educational institutions, with high requirements for noise and dust reduction. “With technology support, we aim to minimize the impact of construction on nearby residents.”

Wang said that inside the membrane, construction noise is about 80 decibels, while outside it’s around 65 decibels, meeting relevant standards and showing significant noise reduction effects. “With the membrane, you can hardly hear the machinery’s roar,” said a nearby resident.

Currently, with the help of the membrane, earthwork has been completed smoothly, and underground structural work is on schedule.

The air-supported foundation pit membrane is highly technological.

The upper part is an air-supported membrane structure, and the lower part is a reinforced concrete frame. The fully enclosed structure effectively reduces construction noise. The membrane is equipped with spray facilities and large fog cannons to prevent dust from spreading. Additionally, during construction, no load-bearing beams or columns are used, and the internal height approaches 50 meters. The membrane fabric is made of new materials that block UV rays and have high heat reflectivity and heat dissipation, ensuring spacious working conditions and worker comfort.

In Jinan’s urban development, the membrane has various applications. To effectively address noise during foundation excavation, during the construction of the Longao Building Station on the first phase of the Metro Line 7, the construction team innovatively used a mobile membrane structure with air ribs, covering the entire foundation pit with a sliding rail-based air-supported membrane. The structure, with intersecting large and small air ribs, can be moved or extended as needed, providing space for excavation and material handling.

“During construction under the membrane, the noise difference inside and outside is about 20 decibels, reducing the impact of subway construction on the outside and improving work efficiency,” said Du Lele, project manager of Metro Line 7.

In the future, this construction method will be promoted in municipal projects and historic district renovations in Jinan, providing a new “silent mode” solution for urban development.

Preventing and Controlling Transportation Noise —

High-Speed Rail Passing Through “Soundproof Tunnels”

Today, taking high-speed trains has become one of the main ways to travel. However, the convenience and speed of high-speed rail can sometimes cause minor issues, such as the loud noise generated when trains pass.

The noise from high-speed trains mainly consists of aerodynamic noise and wheel-rail friction noise. Usually, high-speed rail lines are far from residential areas, but when they must run near urban districts, how is noise addressed?

It’s like giving high-speed trains “noise-canceling headphones”! “Building on the concept of noise-canceling headphones, we use active noise control and have designed fully enclosed sound barriers for high-speed trains,” said Huang Chun, project manager of the China Railway Electrification Bureau’s Guangzhan High-Speed Rail Sound Barrier Project. Compared to the upright sound barriers on highways, these fully enclosed barriers are like building a “soundproof tunnel” on the bridge where the train runs, effectively reducing and cutting down noise frequencies and decibel levels.

By December 2025, the Guangzhan High-Speed Rail will officially open. The fully enclosed sound barrier on the Gaoyang Overpass of the line is particularly eye-catching.

“This overpass is located in Nanhai District, Foshan City, Guangdong Province, only about 10 meters from the nearest residential building, with a middle school about 40 meters away,” Huang explained. Without soundproofing measures, the noise from passing trains would impact residents’ daily lives.

This “soundproof tunnel” is 2.5 kilometers long, 11.8 meters wide, with a center height of 8.97 meters, and features innovative metal sound-absorbing panels made of high-strength aluminum alloy plates, sound-absorbing materials, and cavity structures.

“Sound is essentially a form of energy. We guide the noise through the holes in the sound-absorbing panels into the porous sound-absorbing materials, then use internal friction and blocking to convert sound energy into heat, achieving noise reduction,” Huang said.

Constructing the sound-absorbing panels is complex. To prevent airflow vibrations caused by high-speed trains from causing the panels to fall off, the construction team installed stainless steel cables on both sides of each panel, acting like “safety belts,” ensuring that the panels won’t fall or be damaged when trains pass at high speed.

Huang Chun added that test results show that high-frequency noise generated by trains can be repeatedly refracted and attenuated inside the enclosed barrier, stabilizing at about 20 decibels of reduction.

From the first use on the Beijing-Xiong’an Intercity Railway to iterative upgrades for high humidity and corrosive environments on the Guangzhan High-Speed Rail, fully enclosed sound barriers enable nearby high-speed trains to pass quietly.