If you can hear yourself think in Hong Kong, it's because of an expanded noise pollution rule introduced by the local government.

Hong Kong's government has announced the "Noise Control (Construction Work Designated Areas) (Amendment) Notice" to update the coverage of designated areas under the Noise Control Ordinance. A spokesman for the Environmental Protection Department said in a statement that designated areas were first established in 1996 and were expanded to the existing coverage in 2001 to take account of the development over the years.

Under the amendment notice, the designated areas will be expanded to include newly developed populated built-up areas; areas where development has been actively taking place and population intake is expected to start within the coming few years; and other populated built-up areas in the territory not yet covered. Some areas adjoining the existing designated areas which form parts of the communities have also been identified for inclusion.

"The amendment will provide residents in the new designated areas with the same protection against construction noise as those in the existing designated areas. It is estimated that more than 280,000 residents will benefit from the implementation of the proposal," the spokesman said.

The new designated areas will take effect from January 1, 2009 to give the construction industry time to prepare.