The first "noise map" of a UK city is being launched as part of an attempt to discover how many people live in homes exposed to the roar of traffic and factories.

Birmingham City Council has developed state-of-the-art Sound Immission Contour Maps (SICMs), which are colour-coded maps of combined sources of noise of the city.

The constant din of lorries, cars, planes, trains and other nuisances at "unacceptable" levels is believed to affect as many as 12 million people in the UK.

The maps have implications for local councils when drawing up planning and transport schemes.

Lawnmowers

They have been developed ahead of a potential EU directive and are part of a government-backed plan to cut noise pollution.

Environment Minister Michael Meacher is due to attend a seminar to launch the noise maps.

He said he hoped the forthcoming urban White Paper would provide an opportunity to focus on what could be done to improve the quality of life in cities.

The initiative follows the strengthening of city council powers under the Noise Act to deal with noise created by loud music at parties, loud appliances such as lawnmowers and drills, and domestic arguments.