Environmental Noise Research - CALM, AEN, SILENCER

Ever heard of CALM, AEN, Harmonoise or SILENCE(R) and wondered “what’s that?” Want to know more about the latest research into the causes, effects, assessment and reduction of environmental noise? Need an overview of what the European Commission is doing to support noise policy making? Find some of the answers here.

Introduction
The European Union Noise Policy Green Paper [1] led to an increase in research into areas of environmental noise where knowledge was lacking and methods inadequately developed. Concurrently, several projects financed by the European Union and national government have been started to produce common methodology to ensure the quality of the work behind the new noise policies and to provide a common foundation for comparative statistics. CALM gives an overview of these.

CALM – Community Noise Research Strategy Plan
To support development of the EU’s noise policy and define the strategic plan for future noise research, the European Commission supported the creation of the CALM thematic network [2]. The objective of the CALM network is to establish a Community Noise Research Strategy Plan based on the work and reports of expert Noise Working Groups appointed by the European Commission and in cooperation with the relevant industry sectors, research institutions and interest organisations. The aim is to clearly identify links and gaps between current noise abatement technology and future EU noise reduction and regulation goals in the fields of air traffic, road and rail transport, marine technologies and outdoor equipment. The project budget is over 600,000 €. Started in late 2001, the project is due for completion after three years (i.e., 2004).

In July 2002, the CALM Strategy Paper called “Research for a Quieter Europe” was issued. This sets the research priorities for environmental noise reduction in accordance with the goals of the EU noise policy. The CALM website database currently has over 400 Noise Research Projects and related information with special focus on EU and Member State projects.

The Environmental Noise Directive requires strategic noise maps based on the new harmonised noise indicators and on common methods. However, dose-effect relationships are currently unavailable [3]. The following research requirements have been identified:

• Advanced noise mapping methods
• Availability of noise mapping input data
• Improved measures of the “dose-effect relationships” between noise emission and noise perception (to improve assessment of noise nuisance like annoyance or sleep disturbance)

On the basis of the strategic noise maps, authorities must draw up action plans to reduce noise where necessary and to maintain environmental noise quality where it is good. EU guidelines are to be produced to help member states develop action plans. This requires research into the economic aspects of noise pollution and noise abatement (improved cost-benefit analyses and cost distribution), and into how to optimise the organisation of abatement work at different authority levels such as local, regional, national, EC or international.

Reducing noise at its sources is an essential element in European noise policy and is focused on the principal sources – mainly transport systems and equipment used outdoors such as construction machinery, lawn mowers, etc. To satisfy more stringent legislative limitations and to fulfill the strategy’s vision, solutions to the most significant technical noise problems are needed.

The goal of halving the perceived level of road traffic noise by 2020 requires research into rolling noise demanding low noise tyres and quiet, maintainable road surfaces as well as propulsion noise from the engine, transmission and exhaust, and traffic management.
For rail traffic, targets for noise reduction at source are up to 20 dB(A) for freight trains and 5 dB(A) for high-speed trains. The major areas of further research are rolling noise (mainly for freight trains), curve squeal, brake screech noise and aerodynamic noise.

For air traffic, research into noise reduction of the aircraft in addition to optimised aircraft operation is planned to meet the target for 2020 of a 10 dB noise reduction per operation.

Another target is to halve the noise annoyance caused by outdoor equipment. This requires research into in-use compliance, how single and combined noise sources affect noise perception, and the correlation between noise emission, performance parameters and real operation nuisance.

European Noise Expert Working Groups AEN and HSEA
The European Commission has formed 2 Noise Expert Working Groups:

The first group is the "Assessment of Exposure to Noise" Working Group (AEN). This was given 2 years (ending at the end of 2003) and the following scope [4]:

1. Assist in drawing up guidelines on interim computation methods
2. Identify and develop good practice for noise mapping and to determine associated information on the noise exposure of people, including multi-exposition, quiet zones and industrial noise
3. Assist in developing guidelines on the format in which Member States should provide the data to the Commission
4. Assist on the means through which the results, produced using adapted national methods, can be compared to the results that would have been produced with the interim methods
5. Establish a database of existing noise mapping software, including information on the national computation methods included. In addition, specify a study to define benchmarks to evaluate such software
6. Consider the need for harmonized measurement methods (at a later stage and if considered necessary)
7. Assist the Commission with developing further work on environmental noise

The second group, "Health and Socio-Economic Aspects" Working Group (HSEA), was given the same period to work on [5]:

1. Establishment of dose-effect relations for assessing the effects of noise on populations for noise from road, rail and air traffic and for industrial noise. These include:
   a. Dose-effect relations for LDEN & annoyance
   b. LNight and sleep disturbance for transportation noise
   c. For industrial noise, to multi-exposure situations, and also to the influence of quiet façade, insulation, quiet periods, climate/cultural effects, combination of different health effects, etc.
   
2. Provide input regarding the evaluation of the effectiveness of different noise mitigation measures, and the interaction between measures taken to tackle noise at source and measures taken at the local level.
3. Recommend costs and benefit analysis (CBA) in the field of noise policy, and provide examples of best practice
4. Advise on the format in which Member States should provide data to the Commission and how the public shall be informed
5. Develop action plan guidelines, in particular for quiet zones, and provide a common framework to be used when carrying out a CBA for an action plan
6. Assist in developing further work on environmental noise (e.g. reviewing expectations of the public, of the use of ISO or WHO standards, etc.)

Work from both groups is published on the European Commission’s home page as it is completed.

Harmonoise
One important project is the Harmonoise project [6] to develop a new, common European road and railway noise mapping calculation method for use in the noise maps to be made for 2012 and onwards. Harmonoise includes 19 partners and, by August 2004, will develop:

• Reference models: for more accurate determination of noise levels. This will include a source description method for road and rail sources and improved and extended prediction methods for outdoor noise propagation
• Engineering methods that integrate the source description models and propagation models for use in noise mapping. This should be able to calculate large models with accuracies of within 1 dB(A), standard deviation, up to 100 m, within 2 dB(A) up to 2000 m on a flat terrain and within 5 dB(A) behind hills and urban situations [7]
• Assessment of accuracy for prediction of long-term averaged noise indicators in complex situations

SILENCE(R)
The largest ever aircraft noise research programme to be supported by the European Commission [8], SILENCE(R) is run by a consortium of 51 companies and has a budget of over 110 million €. They will collaborate over four years from April 2001 to March 2005 to validate noise reduction technologies that will allow quieter aircraft operations by up to 6 dB, as of 2008:

1. Large-scale validation of noise reduction technologies currently existing or under development (e.g. low-noise fans, active control techniques and airframe noise reduction technologies)
2. Assessment of the applicability of these technologies to current and future European products with minimum cost, weight or performance penalty.
3. Determination of the associated achievable noise reduction.

References
1. “Green Paper on Future Noise Policy (COM(96) 540)”, European Commission (1996)
2. www.calm-network.com
3. “CALM - An EU Network for Strategic Planning of Future Noise Research”, Rust & Affenzeller, Proceedings of Euronoise 2003
4. www.harmonoise.org
5. “The Harmonoise engineering model”, van Leeuwen & Nota, Proceedings of Euronoise 2003

Read more about the Environmental Noise Directive and Brüel & Kjær-related products and solutions.