Environmental acoustics: atmospheric effects on outdoor sound propagation

Noise is a major societal problem, with a proven impact on health (hearing impairment, development of cardiovascular problems, stress, insomnia, etc.), particularly in urban and suburban areas where noise sources are numerous and varied. This health impact has a significant cost for society, now quantified and estimated at over 1 million DALYs (Disease Adjusted Life Years, DALYs), based on five targets including sleep, cardiac ischemia and learning disabilities (source: WHO, "Burden of disease from environmental noise. Quantification of healthy life years lost in Europe", 2011, http://www.euro.who.int/__data/assets/pdf_file/0008/136466/e94888.pdf ).

In 2000, the IPSOS polling institute revealed that noise was the nuisance most cited by French households (30% of the population surveyed), on a par with air pollution (29% of respondents, source: IPSOS 2000, http://www.ipsos.fr/CanalIpsos/articles/539.asp ). A subsequent INSEE study published in October 2002 shows that, in urban areas with more than 50,000 inhabitants, residents put noise ahead of insecurity when it comes to ranking the most worrying local problems (source: INSEE 2002, http://www.insee.fr/fr/ffc/docs_ffc/IP885.pdf ). Opinions on environmental issues may have changed in recent years, but noise remains one of the main concerns of French residents in urban areas, as shown by the latest TNS-SOFRES (source 2010: http://www.tns-sofres.com/_assets/files/2010.06.29-nuisances-sonores.pdf ) and IPSOS (source 2014: http://www.ifop.com/media/poll/2799-1-study_file.pdf ) surveys, as well as the 2014 edition of the report on the environment (source: Ministère en charge de l'écologie et du développement durable, 2014, https://www.ecologie.gouv.fr ). In urban environments, traffic is very frequently...