{"id":600,"date":"2010-09-16T16:20:10","date_gmt":"2010-09-16T06:20:10","guid":{"rendered":"http:\/\/blog.dbohs.com\/?p=600"},"modified":"2010-09-16T16:21:30","modified_gmt":"2010-09-16T06:21:30","slug":"calculating-laeq-from-a-series-of-decibels","status":"publish","type":"post","link":"https:\/\/blog.dbohs.com\/?p=600","title":{"rendered":"Calculating LAeq from a series of decibels"},"content":{"rendered":"<p>The <strong>equivalent sound pressure level L<\/strong><sub><strong>eq<\/strong><\/sub><strong> <\/strong>for an eight hour day with a sound level varying as <em>L<sub>p<\/sub>(t).<\/em><\/p>\n<p><em><a rel=\"attachment wp-att-602\" href=\"http:\/\/blog.dbohs.com\/?attachment_id=602\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-602\" title=\"Leq formula\" src=\"http:\/\/blog.dbohs.com\/wordpress\/wp-content\/uploads\/Leq-formula.png\" alt=\"\" width=\"232\" height=\"71\" \/><\/a><br \/>\n<\/em><\/p>\n<p><!--more-->You rarely know L<sub>p<\/sub>(t) \u2013 the pattern of noise exposure over the day, but sometimes the data is available, but a censored set of the data is used, perhaps just to look at the equivalent sound pressure level from a particular machine.<\/p>\n<p>For a series of noise measurements at regular intervals, the L<sub>eq<\/sub> can be calculated in Excel with the following \u201c<strong>array formula<\/strong>\u201d \u2013 a powerful but little known feature in Excel.<\/p>\n<p style=\"text-align: center;\">=10*LOG10(AVERAGE(10^((<span style=\"color: #ff0000;\">your range<\/span>)\/10)))<\/p>\n<p>When the range \u2013 say the cells D1 and D2 are selected and the <strong>Shift+Control+Enter<\/strong> keys are pressed simultaneously, the formula bar in Excel will show the formula enclosed in {}<\/p>\n<p><a rel=\"attachment wp-att-603\" href=\"http:\/\/blog.dbohs.com\/?attachment_id=603\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-medium wp-image-603\" title=\"excel Leq grab\" src=\"http:\/\/blog.dbohs.com\/wordpress\/wp-content\/uploads\/excel-Leq-grab-300x108.png\" alt=\"\" width=\"300\" height=\"108\" srcset=\"https:\/\/blog.dbohs.com\/wordpress\/wp-content\/uploads\/excel-Leq-grab-300x108.png 300w, https:\/\/blog.dbohs.com\/wordpress\/wp-content\/uploads\/excel-Leq-grab.png 380w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>If you just used the arithmetic average you would get 47.5, the wrong answer.<\/p>\n<p>If you try to use an Excel VAB macro with that formula, \u00a0it wont work as VBA does not have Log10() &#8211; you have to use Log(X)\/log(10).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>How to calculate Leq with an array formula in Excel<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[94,20],"tags":[120,123,122,121],"class_list":["post-600","post","type-post","status-publish","format-standard","category-noise","category-occupational-hygiene","tag-excel","tag-leq","tag-macro","tag-vba","czr-hentry"],"aioseo_notices":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=\/wp\/v2\/posts\/600","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=600"}],"version-history":[{"count":7,"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=\/wp\/v2\/posts\/600\/revisions"}],"predecessor-version":[{"id":609,"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=\/wp\/v2\/posts\/600\/revisions\/609"}],"wp:attachment":[{"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=600"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=600"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.dbohs.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=600"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}