GREATER UNDERSTANDING OF HOW SOUND ENVIRONMENTS AFFECT OUR HEALTH
Regulations on the work environment state that noise is hazardous to health at decibel levels at which it can cause direct damage to hearing. However, recent research has shown that noise can be detrimental to health even at relatively low decibel levels. Moderate levels of traffic or railway noise elevate risks of sleep disturbances, high blood pressure, diabetes and cardiovascular disease. This low-frequency noise causes premature death to roughly the same extent as road accidents.
Soundscape Support to Health provided new knowledge of the overall sound situation in various kinds of urban environments, how people perceive it and how it affects their health. Scientists in acoustics, environmental medicine and environmental psychology have measured sleep quality, stress levels and other health factors in experimental subjects.
WHAT RESULTS HAS THE PROGRAMME HAD?
The programme participants have devised new approaches, known as ‘soundscape thinking’ and ‘soundscape concepts’, that can be applied when new housing areas are developed and to improve the sound situation in existing residential environments. The researchers have proposed sound limits for public transport and speed limits for transport in housing areas.
‘A positive soundscape in the residential environment is good for public health, as the programme has shown. But with growing traffic and populations of urban areas, ever fewer people get access to such a soundscape. The programme developed tools to improve, and engage in long-term planning of, positive soundscapes in our housing areas. This is a very good societal investment.’
Barbro Westerholm, Member of the Riksdag and executive committee chairman
They have also found that noise exerts various effects on health, depending on whether the sounds are perceived as unpleasant (traffic, the whirring of fans and other technical sounds) or pleasant (birdsong, the rustling of trees and other natural sounds). Within the framework of the programme, a method based on walking surveys of the sound environment — the ‘Soundscape Walk’ — has been devised to assess sound quality in residential areas and parks.
One of the most important results was the discovery of the importance of a ‘silent side’ to the home or housing area. The programme also defined the notion of a silent side and it was adopted in the EU Environmental Noise Directive 2002/49/EC.
Within the scope of the programme, soundscapes, perceived disturbance and health were surveyed in and around similar homes with and without a silent side. Criteria for health-promoting soundscapes have also been formulated. The research group was, moreover, able to demonstrate shortcomings in the limit values for noise that exist and in methods of measuring sound quality, including the quality of sound in inner courtyards. In addition, knowledge of how various forms of screening and ways of splitting up transport flows affect traffic noise in residential areas.
WHO HAS BENEFITED FROM THE RESEARCH?
All those who plan and build new housing areas are benefiting from the results. Public agencies engaged in housing construction and urban planning have used the research. For new housing construction, the Swedish National Board of Housing, Building and Planning has introduced requirements for a silent side to homes. Today, hardly any apartments lacking access to a planned silent side are built in Sweden.
The National Board of Health and Welfare and the Swedish Environmental Protection Agency refer, in various publications and contexts, to the results of the programme. The latter agency has also cofounded a knowledge portal, which was launched towards the end of the programme. Based on the findings from the research programme, this portal reports and updates research findings and news in the area; see http://www.ljudlandskap.acoustics.nu/ljudbok.php.
In the EU, the provisions of the Environmental Noise Directive about silent areas and the silent side are also based to a high degree on results from the research programme. Researchers on the programme played an active part in the groups that drew up the Directive, which has been implemented in Swedish legislation through the Ordinance (2004:675) on environmental quality standards for noise, and which serves as an environmental quality norm.