In April, an elderly tenant surnamed Wang, living in flat 702 of an apartment complex in Shanghai’s Pudong area, was woken up at around 2 a.m. by a sound that went “tock, tock, tock.”

It was, she says, “Like someone knocking a wooden fish (a Buddhist percussion instrument) on the floor.” She counted ten knocks in all — but it was still ten fewer than the night before.

The noise didn’t end there. The flat 702 resident describes what followed as ear-piercing shrieks, chaotic radio static, and the sound of several people talking simultaneously — all echoing across her house at unbearably loud volumes. “It put so much strain on my heart I thought I’d die,” she said.

And it wasn’t the first time. The persistent din meant her octogenarian husband was often groggy from lack of sleep. On Aug. 24, 2018, he sat in the living room wide awake until dawn. When he finally stood up, he was overcome by a wave of dizziness and fell, fracturing four ribs. In a similar incident in May 2019, he fractured another rib.

For five years, the couple in flat 702, along with most other residents in this Shanghai apartment complex, have been overwhelmed by this relentless racket.

It began after an argument over water dripping into flat 502’s balcony from the floor above and quickly spiralled out of control. When talks reached an impasse, the residents in flat 502 turned to extreme measures: they deployed a “floor-shaker.”

Shaped like mops and priced at around 200 yuan ($30), such gadgets are built around vibrating motors originally designed to run industrial sieves. They come with multiple modes: vibration only, pounding only, or a combination of the two. A fourth option activates both, along with other random sounds including static, persistent knocks, and even piercing shrieks.

The floor-shaker serves one purpose: when installed on the user’s ceiling, the deafening noise it makes is projected into the house above — in this case, into flat 602, literally shaking their floor.

But such is the gadget’s capacity to exact vengeance that for five years, its perpetual use terrorized not just flat 602 but the entire 11-storey apartment. When attempts at reaching a compromise with flat 502 failed, other residents of the building tried calling the police and filed complaints, petitions, and even lawsuits.

But the occupants of flat 502 stayed adamant; the cacophony did not stop.

Until April 30, 2021. That’s when both neighbors called a truce after the feud triggered widespread media attention. Since then, the silence returned, as have several residents who had moved out to escape the din. One elderly homeowner who “hadn’t slept all year round” says his “old life had been saved.”

Others are still worried though. They say the truce between the two neighbors at the epicenter of the feud is tenuous at best, and fear that the ear-splitting racket might return any day.

Knocks, shrieks, and static

When the first rumblings began in 2017, a second-floor resident went upstairs to visit Wang in flat 702, the head of the building’s residential committee at the time. “[The 2nd floor resident] thought there was an earthquake, because a tea cup on a stool was gently rattling,” says Wang.

A former occupant of flat 802, who moved out in the fall of 2020, says about that time, “Everyone who sold their apartment did so at least partly because of the noise ... Nobody really wanted to sell — they just didn’t have a choice.”

Residents say the neighborhood committee, the police, and other authorities repeatedly investigated the source of the racket. But every time they approached flat 502 — the owners of the floor-shaker — its occupants refused to answer the door.

But they knew who was responsible: When electricity to flat 502 was cut, the noise immediately ceased.

Flat 502’s primary target is 602. In a complaint letter to the head of the Pudong New Area, an occupant of flat 602, a woman also surnamed Wang but not related to the elderly Wang of flat 702, stated that she was forced to sleep in the living room, where the noise was softer.

In her letter, the younger Wang described the noise as a looping series of “piercing, high-decibel, low-frequency” sounds such as “rusty gears turning, toilet bowls flushing, small children wailing, and someone knocking a wooden fish.”

On April 29, a reporter of the local Xinmin Evening News visited flat 602, where a phone app that measures sound levels showed the noise was above 60 decibels. This far exceeded normal levels — no greater than 30 decibels from 10 p.m. to 6 a.m., and no more than 40 decibels during the day.