Developments worth more than HK$10,000 per square foot in The Arch, another in The Waterfront and one block in the Sorrento above Kowloon Station will all face noise levels above the acceptable 75 decibels during construction, despite sound-proofing measures.

Engineers say 70 to 75dB of noise is equivalent to having a busy road directly outside an apartment.

The 26-kilometre Hong Kong section will be built entirely underground and run from the West Kowloon terminus to the mainland via Mong Kok, Kwai Tsing District, Tsuen Wan and Mai Po.

Despite construction getting under way by the end of the year, residents in the areas to be affected have not received information about the potential noise impact.

The Executive Council has given approval to the cross-border express railway with a price tag of HK$65.2 billion. Land owners from Tsoi Yuen Tsuen first drew the public's attention to the railway when they began protesting about the demolition of their homes to make way for a depot.

The MTR Corp's environmental impact assessment report named several areas - described as noise-sensitive zones - that would most likely be affected by noise. The report shows public housing estates, homes for the elderly, village houses, schools and luxury flats within the zones.

It recommends that for homes for the elderly, construction noise, after mitigation measures, should not exceed 70dB, the equivalent of the noise generated by a vacuum cleaner. It also sets the daytime construction-noise maximum for schools at 65dB during examinations and 70dB during normal school hours.

However, the report predicts that Ying Wa College, Sham Shui Po, will suffer noise of up to 70dB; Yaumati Catholic Primary School up to 74dB; and that noise pollution at HKIVE Haking Wong Waterfront Annex on Lai Chi Kok Road may exceed the recommended maximum by 3dB to 7dB for about 34 months.

Luxury developments in West Kowloon are not to be spared. Sky Tower at The Arch will have noise levels of up to 70dB, while its neighbouring Moon Tower will suffer up to 76dB. Tower 3 of The Waterfront on top of Kowloon Station will hear levels of up to 78dB.

The report also points out that after the line opens the residents of Shui Hong Nursing Home at Cheung Shan Estate, Kwai Chung, will face continuing noise from a ventilation shaft about 75 metres away. Chan Wing-hung, a social worker at the home, expressed concern for the health of the 100 residents aged 60 to 96. 'I have not yet received any notice about the rail. We will study the impact if we are informed and, if problems affect us, we will speak out.'

Ying Wa College has 1,200 pupils and its primary section, Ying Wa Primary School, has 1,000. But principal Roger Lee Chee-wah said he had little information on how the project would affect the school.

'Our school has not yet received any consultation on the railway. I have not yet received phone calls or letters,' he said. 'The predicted noise of 70 decibels falls within the criteria. But ... the standard should be stricter for schools. Students need a quiet environment for learning.'

The situation was somewhat different at HKIVE Haking Wong, a vocational training school. Principal Winnie Ngan Shuk-yin said the annex on Lai Chi Kok Road was used as an electrical workshop. 'Representatives of related parties had meetings with us. We also agreed that the construction works would be temporarily suspended if needed. Actually, students do drilling at the workshop, which also creates noise. So the rail works would not affect us much.'

Fu Cheong Estate, across the road from Ying Wa College, has two blocks expected to be affected by construction noise. But nine of 10 residents interviewed said they had no idea on how construction work would affect their lives.

Leung Kin-hoi, 25, who lives with her husband and child at the estate, said she was worried about the impact on health. 'I have not heard of construction works near my estate. I worry that it might affect my child's studies and health. Noise would disturb my child's sleep,' she said.

Kenny Wong Kai-ming, 22, who lives in Tower 1 of The Waterfront, said he did not know the location of the railway but was concerned that the noise might disturb his studies.

The report said the contractor should liaise with schools and avoid noisy construction work during examinations. It also recommended that mitigation measures such as silencers and mufflers be used on construction equipment.

Peter Wong Yiu-sun, a former president of the Institute of Engineers, said that the heavy machinery used in the early stages of construction would be quite noisy.

'Preparation of the construction site, especially moving heavy machines or drilling the first hole in the ground, will cause noise,' he said.

'But the impact also depends on ambient noise and the distance of affected parties from the source of the noise.'

Maggie So Man-kit, senior manager of projects and property communications at the MTR Corp, said equipment and site practices would aim to keep noise to a minimum. However, there would be times when noise would be unavoidable.

She said the contractors would be instructed to work with schools and community facilities such as nursing homes, and that public forums and meetings with owners committees had been organised. The committees of the properties on top of Kowloon Station had been informed via their management offices.

MTR Corp general manager of the express rail link, Paul Lo Po-hing, pledged the company would take all measures possible to reduce environmental noise and vibration from the project.

'We have to submit the environmental assessment report before the construction. We have to get the permit before starting construction. In the permit, we would outline the measures to be taken,' he said.

Meanwhile, the Transport and Housing Bureau said it would ensure the project complied with the conditions on the environmental permits.