Europa
http://europa.eu.int
This is a general purpose site
http://europa.eu.int/comm/environment
Comprehensive Information Resource on Europe. Includes, among others,
http://europa.eu.int/comm/environment/newprg/index.htm
Sixth Environmental Action Plan COM(2001)31: 'Environment 2010: Our Future, Our Choice'.. Has links to press release, full text, executive summary, book list. Emphasis on sustainability issues.
http://europa.eu.int/eur-lex/en/
General EU site for documents, directives, legislation etc. Use search for "Noise". for example.

The European Environment Agency
http://www.eea.eu.int
EEA Mission: to gather and disseminate comparable data to policy-making agents and the public. Formed 1993 by the EU, works in collaboration with EIONET (European Information and Observation Network which is co-ordinated by EEA. Noise Section has 10 Reports listed and 13 Useful Links.

The X-Noise Network
http://www.nlr.nl/public/hosted-sites/x-noise/home.html
Dedicated to aircraft noise reduction efforts in Europe. 
Select 'Network Activity' for the 7 objectives concerning the promotion of aircraft noise reduction research and technology, lists Committees and Expert Groups. 
Select 'Associated Projects' for details of these projects DUCAT, RESOUND, RANNTAC, RAIN, SOURDINE 1 & 2, TurboNoiseCFD, JEAN, SILENCE(R). {SILENCE(R) is the largest aircraft noise research programme supported by EEC, launched01/04/01. 51 companies, 14 countries, 4 years; aim 6 dB reduction by 2008, part of the 5th Framework Programme.)
Select 'Other Noise Projects' for details of FANPAC, SNAAP, APIAN, AEROCERT.
Select http://www.nlr.nl/public/hosted-sites/x-noise/othernet.html#cib1
for 'Other Networks' with ENOVNET, TRA3, NOCOMAT.