At night, Zhang had to wear headphones and play white noise, but he still woke up frequently. After using a measuring device, he discovered the loudest sound, reaching 39 dB, originated from his bedroom wall. Inquiring with his neighbor, Zhang found the source was an aquarium oxygen pump placed against the wall. The noise only stopped when the fish tank was moved.

The type of sound affecting Zhang is known as low-frequency noise (20-200 Hz). This range of noise primarily travels through building structures; it has a low volume, is hard to pinpoint, but possesses strong penetrating power. Medical studies indicate that prolonged exposure to low-frequency noise can lead to hearing impairment, neurological disorders, and cardiovascular system disturbances.

In 2025, China recorded over 6,8 million noise complaints, with the majority related to these difficult-to-measure sounds. However, current measurement standards often fail to fully assess the impact of low-frequency sounds, making it challenging for many victims to file complaints.

In Shanghai, Li Qian and her husband moved into an apartment in Qingpu District in 2023. Every evening, she heard intermittent sounds lasting until dawn, causing ringing in her ears and chest tightness. In 10/2023, Li Qian identified the source as the water pump room on basement level B1, located beneath her bedroom. A noise measurement app showed sound levels around 70 dB, in the 50-200 Hz frequency range. Regulatory authorities inspected and concluded it "did not exceed standards", and the building management refused to address the issue.

Li Qian had to move out and rent another place for about 450 USD a month. By 6/, she hired an independent firm for an inspection, which recorded four exceeding parameters, and she prepared over 14,000 USD in legal fees to sue the developer.

In Shijiazhuang, Hebei province, Xiao Shan reported hearing machinery roaring in the early morning. The source was identified as the cold storage system of a butcher shop on the first floor. After continuous complaints, the shop owner finally agreed to install soundproofing and turn off the machinery after 22h.

Zhu Lin visited a resident's home to listen to the noise. *Photo: QQ*

Zhu Lin, an acoustics expert who has consulted on nearly 100,000 cases, believes that the surge in low-frequency noise is due to aging infrastructure systems (transformers, pumps, central air conditioning) built many years ago. Identifying the source requires significant effort. In 7/, Zhu Lin spent two days measuring before discovering that 78 Hz noise affecting residents in two buildings in Weifang (Shandong province) originated from a gas pipeline in the basement.

Legally, China's amended Ecological and Environmental Law will take effect on 15/8/2026. The breakthrough is that judicial bodies will no longer use "exceeding standards" as the sole criterion. In the first case heard on the same day, the court ruled that if business activities continuously disrupt residents' normal lives, such conduct still constitutes a legal violation.

While awaiting technical solutions, expert Zhu Lin advises residents to try to perceive this as white noise to stabilize their mindset and avoid excessive anxiety that could lead to auditory hallucinations. Immediate measures such as using a fan to create background noise, moving beds a few centimeters away from walls, and stuffing fabric into gaps can help reduce vibrations transmitted to the body.

Bao Nhien (According to QQ)