{"id":15714,"date":"2011-06-25T21:03:30","date_gmt":"2011-06-26T01:03:30","guid":{"rendered":"https:\/\/www.windturbinesyndrome.com\/static\/static\/?p=15714"},"modified":"2012-01-21T12:30:45","modified_gmt":"2012-01-21T17:30:45","slug":"the-bigger-they-are-the-more-lfn-denmark","status":"publish","type":"post","link":"https:\/\/www.windturbinesyndrome.com\/static\/2011\/the-bigger-they-are-the-more-lfn-denmark\/","title":{"rendered":"The bigger they are, the more LFN (Denmark)"},"content":{"rendered":"

\"\"<\/a><\/p>\n

\u00b7<\/span>
\n\u2014Henrik M\u00f8ller & Christian Sejer Pedersen<\/span> (click here<\/a> for PDF of the article)<\/p>\n

“Low-frequency noise from large wind turbines,” Journal of the Acoustical Society of America<\/em>, vol. 129, no. 6, June 2011, pp. 3727-3744.<\/span><\/p>\n

\u00b7<\/span>
\nAbstract<\/em>:<\/h6>\n

As wind turbines get larger, worries have emerged that the turbine noise would move down in frequency\u00a0and that the low-frequency noise would cause annoyance for the neighbors. The noise emission\u00a0from 48 wind turbines with nominal electric power up to 3.6 MW is analyzed and discussed.<\/p>\n

The relative amount of low-frequency noise is higher for large turbines (2.3\u20133.6 MW) than for\u00a0small turbines (\u00022 MW), and the difference is statistically significant. The difference can also be\u00a0expressed as a downward shift of the spectrum of approximately one-third of an octave.<\/p>\n

A further\u00a0shift of similar size is suggested for future turbines in the 10 MW range.<\/p>\n

Due to the air absorption,\u00a0the higher low-frequency content becomes even more pronounced when sound pressure levels in\u00a0relevant neighbor distances are considered.<\/p>\n

Even when A-weighted levels are considered, a substantial\u00a0part of the noise is at low frequencies and, for several of the investigated large turbines, the\u00a0one-third octave band with the highest level is at or below 250 Hz.<\/p>\n

It is thus beyond any doubt that\u00a0the low-frequency part of the spectrum plays an important role in the noise at the neighbors.<\/p><\/blockquote>\n

\u00b7<\/span>
\nEditor’s note<\/em>: \u00a0A close reading of this article shows that it invokes some <\/span>outdated assumptions<\/a> to reach its conclusions—rendering those conclusions flawed. \u00a0As with the following: <\/span><\/p>\n

The turbines do emit infrasound (sound below 20 Hz),\u00a0but levels are low when human sensitivity to these frequencies\u00a0is accounted for. Even close to the turbines, the infrasonic sound pressure level is much below the normal hearing threshold,\u00a0and infrasound is thus not considered as a problem with\u00a0turbines of the investigated size and construction.<\/span><\/p>\n

In the main, however, M\u00f8ller and Pedersen are to be commended for heading in the right direction.<\/span><\/span><\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

\u00b7 \u2014Henrik M\u00f8ller & Christian Sejer Pedersen (click here for PDF of the article) “Low-frequency noise from large wind turbines,” Journal of the Acoustical Society of America, vol. 129, no. 6, June 2011, pp. 3727-3744. \u00b7 Abstract: As wind turbines get larger, worries have emerged that the turbine noise would move down in frequency\u00a0and that the low-frequency noise would cause annoyance for the neighbors. The noise emission\u00a0from 48 wind turbines with nominal electric power up to 3.6 MW is analyzed and discussed. The relative amount of low-frequency noise is higher for large turbines (2.3\u20133.6 MW) than for\u00a0small turbines (\u00022 MW), and the difference is statistically significant. The difference can also be\u00a0expressed as a downward shift of the spectrum of approximately one-third of an octave. A further\u00a0shift of similar size is suggested for future turbines in the 10 MW range. Due to the air absorption,\u00a0the higher low-frequency content becomes even more pronounced when sound pressure levels in\u00a0relevant neighbor distances are considered. Even when A-weighted levels are considered, a substantial\u00a0part of the noise is at low frequencies and, for several of the investigated large turbines, the\u00a0one-third octave band with the highest level is at or below 250 Hz. It is thus beyond any doubt that\u00a0the low-frequency part of the spectrum plays an important role in the noise at the neighbors. \u00b7 Editor’s note: \u00a0A close reading of this article shows that it invokes some outdated assumptions to reach its conclusions—rendering those conclusions flawed. \u00a0As with the following: The turbines do emit infrasound (sound below 20 Hz),\u00a0but levels are low when human sensitivity to these frequencies\u00a0is accounted for. Even close to the turbines, the infrasonic sound pressure level is much below the normal hearing threshold,\u00a0and infrasound is thus not considered as a problem with\u00a0turbines of the investigated size and construction. In the main,Read More…<\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[163,16],"tags":[],"_links":{"self":[{"href":"https:\/\/www.windturbinesyndrome.com\/static\/wp-json\/wp\/v2\/posts\/15714"}],"collection":[{"href":"https:\/\/www.windturbinesyndrome.com\/static\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.windturbinesyndrome.com\/static\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.windturbinesyndrome.com\/static\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.windturbinesyndrome.com\/static\/wp-json\/wp\/v2\/comments?post=15714"}],"version-history":[{"count":0,"href":"https:\/\/www.windturbinesyndrome.com\/static\/wp-json\/wp\/v2\/posts\/15714\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.windturbinesyndrome.com\/static\/wp-json\/wp\/v2\/media?parent=15714"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.windturbinesyndrome.com\/static\/wp-json\/wp\/v2\/categories?post=15714"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.windturbinesyndrome.com\/static\/wp-json\/wp\/v2\/tags?post=15714"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}