Retiree Deng Rong finds it ironic that she has become envious of the animals in Beijing Zoo.
The reason? Insulation panels covering a flyover across the zoo were completed a month ago, cutting off the traffic noise.
Deng's home in Yong'anli is 10 metres from Tonghuihe North Road, a major new expressway intersecting the eastern corner of the capital. But there's no noise insulation there, so the roar of cars and trucks has made her life a misery since the road opened a year ago. The din gets so bad there's little peace even when she closes her windows at 3am.
'I can't sleep because of the noise and I have to take pills. So do my neighbours,' says the 63-year-old. 'Why is it that even animals can be protected from the noise but we can't?'
Deng is among the officially estimated five million residents suffering from noise pollution in Beijing, although the actual number is likely to be higher. Noise complaints lodged with the Beijing Environmental Protection Bureau hotline rose from about 9,600 in 2005 to more than 12,000 last year, with more than half related to traffic and construction.
Most blame the city's rapid development - with building sites springing up, more cars and new roads being built to accommodate them - for rising noise levels.
But weak government enforcement of noise limits and poor planning have aggravated the situation.
'[Noise] is a byproduct of urbanisation that every city faces in its development,' says Zheng Jingchun, director of noise control at the Beijing Environmental Protection Bureau. 'It's a complicated issue that needs more than one government department to deal with. Our bureau is just a co-ordinator.'
Under environmental rules that came into effect last year, traffic noise is the responsibility of Beijing's traffic committee, the city administration office and construction bureau deal with construction noise and the public security bureau is responsible for all other noise. This fractured jurisdiction often confuses residents and red tape makes it difficult to tackle noise problems.
After Tonghuihe North Road opened for trial use in October 2006, 300 families submitted joint letters of complaint to the traffic committee, the environmental protection bureau and the planning commission, which disappeared into the mire of bureaucratic buck-passing.
'The environment bureau says we should talk to the traffic committee, and the traffic committee tells us to go to the planning commission. We've been kicked around between these departments for about one year without any result,' says Deng.
Asked about prospects for alleviating the woes of Deng's neighbourhood, Zheng says: 'We're looking into this issue but I can't give you a date when it will be solved or how it will be solved before we have consulted the experts.'
Residents at the Majiapu Jiayuan estate in southern Beijing encountered similar frustrations in July when they complained to the government about relentless noise from a nearby construction site, a racket that went on around the clock, every day of the week. After countless calls to the city administration office, the construction committee and eventually the police, several hundred angry residents blockaded the entrance to the site.
Their action forced the construction company, Dingli, which did not have a permit to work at night, to stop its nocturnal hammering and grinding. But the peace didn't last and the clamour soon resumed.
When a second sit-down protest was staged in August, the company gave in again. After mediation by the local construction committee, Dingli agreed to compensate the residents for their suffering, offering to pay each household 60 yuan a month - the nationwide cap on compensation for construction noise.
But once payment was made, the company resumed work at night, unimpeded by official regulators. 'We would rather regain our quiet than accept their money, but it seems they feel they have bought our consent to make noise now,' says resident Feng Wenxue.
However families living in Tiantongyuan, a large housing estate in the city's northern suburbs, were able to overcome their noise woes thanks to a cleverly waged campaign.
After more than a month of fruitless protests over clatter from a new light railway running through the estate, residents contacted four testing institutes to measure sound levels. But once the researchers learned that the assignment involved the No5 light rail, a key government project designed to ease congestion during the Olympic Games, they lost their nerve.
'They were all afraid of getting into trouble because the line is an Olympic project,' says Wang Yunzhi, a computer engineer living in Tiantongyuan.
Unable to get professional help, the residents measured noise levels themselves using borrowed equipment. Wang conducted sound checks in nine homes in July and found that indoor noise levels rose as high as 65 decibels when the train passed, well above the official limit for residential areas of 55 decibels during the day and 45 decibels at night.
The estate's residents presented their findings to local newspapers and the media exposure forced the Beijing Metro Transport Construction and Management Company to agree to introduce noise insulation along the Tiantongyuan section of the line last month.
'Our problem probably would never have been solved if we hadn't checked the noise levels ourselves,' says Wei Jie, a project manager at mobile phone giant Motorola.
Wang Jianghua, a lecturer in architecture acoustics at Tsinghua University, says the mainland sets lower standards than western countries, where the limit for indoor noise is between 30 and 40 decibels.
'We're still putting economic development first,' he says. 'If we impose higher standards, it will be difficult to implement them.'
The loosely defined regulations create plenty of loopholes for unscrupulous developers. For example, many build homes as close to planned roads as they can to make full use of the land. They also use inferior insulation materials to cut costs.
Although the new noise pollution rule requires developers to list the acoustic specifications of properties in sales contracts, it doesn't specify penalties for breaching noise limits. Nor does it prohibit them from building right next to major expressways or railways.
'The government lets house buyers shoulder the liabilities themselves,' says Wang. 'Consumers may win a full refund if noise in a house is found to exceed official limits. But with property prices soaring in Beijing, buyers are in a weak position. Their refund usually isn't enough to buy a similar property now,' he adds.
Poor implementation of planning objectives also contributes to the worsening noise woes, Wang says. Building a road takes years, as it involves getting official approval, clearing the land and relocating residents. But during that period, many applications for new housing projects escape city planners' scrutiny and gain approval to be built next to major transport arteries.
In the case of the No5 light railway, according to the Beijing Municipal Commission of Urban Planning website, the line was planned as early as 1992 but its detailed blueprint was not approved until a decade later. In that time, the Tiantongyuan estate had almost been completed.
'Neither city planners nor environmental officials have the power to stop a substandard project, especially those involving municipal infrastructure,' Wang says.
And even though Zheng's job is to control noise pollution, he suffers from it. His office and his home are perched over major city roads. 'What can I do but bear it? The triple-glazed windows in my home are never open, even in summer.'