{"id":73294,"date":"2019-04-18T13:19:27","date_gmt":"2019-04-18T13:19:27","guid":{"rendered":"https:\/\/www.scantec.it\/en\/?p=73294"},"modified":"2019-04-18T13:34:20","modified_gmt":"2019-04-18T13:34:20","slug":"what-is-the-noise","status":"publish","type":"post","link":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/","title":{"rendered":"What is the noise?"},"content":{"rendered":"<p><strong>Noise is an acoustic disturbance effect, natural or artificial, that have a negative effect with listener\u2019s activity. <\/strong><\/p>\n<p>Parameters to describe the noise are:<\/p>\n<p><strong>Sound pressure:<\/strong> is the difference between the\u00a0pressure\u00a0caused by a\u00a0sound wave\u00a0and the\u00a0ambient pressure\u00a0of the\u00a0medium the sound wave is passing through. it\u00a0is measured in\u00a0Pascal [Pa].<\/p>\n<p><strong>Frequency:<\/strong> the number of times that a\u00a0periodic\u00a0function or vibration occurs or repeats itself in a specified time, often 1 second &#8211; cycles per second. It is usually measured in\u00a0Hertz [Hz].<\/p>\n<ul>\n<li>\u0192&lt; 20 Hz =&gt; infrasound<\/li>\n<li>20 Hz\u00a0 &lt; \u0192 &lt; 20000 Hz =&gt; human perception<\/li>\n<li>\u0192 &gt;20000 Hz =&gt; ultrasound<\/li>\n<\/ul>\n<p><strong>Sound intensity<\/strong>: it is measured in Decibel [dB], a\u00a0logarithmic\u00a0unit used to describe a ratio between the measured level and a reference or threshold level of 0 dB.<\/p>\n<p><strong>Examples of sound pressure, sound level and human evaluation. \u00a0<\/strong><\/p>\n<table width=\"627\">\n<tbody>\n<tr>\n<td width=\"159\"><strong>Sound pressure [Pa]<\/strong><\/td>\n<td width=\"149\"><strong>Sound level [dB(A)]<\/strong><\/td>\n<td width=\"149\"><strong>Sound source <\/strong><\/td>\n<td width=\"170\"><strong>Human evaluation<\/strong><\/td>\n<\/tr>\n<tr>\n<td width=\"159\">20 \u00b5Pa<\/td>\n<td width=\"149\">0<\/td>\n<td width=\"149\">Threshold level of reference<\/td>\n<td rowspan=\"4\" width=\"170\">Relaxed<\/td>\n<\/tr>\n<tr>\n<td width=\"159\">100 \u00b5Pa<\/td>\n<td width=\"149\">10<\/td>\n<td width=\"149\">Threshold level of audibility<\/td>\n<\/tr>\n<tr>\n<td width=\"159\"><\/td>\n<td width=\"149\">20<\/td>\n<td width=\"149\">Leaves rustle, murmur<\/td>\n<\/tr>\n<tr>\n<td width=\"159\">1 mPa<\/td>\n<td width=\"149\">30<\/td>\n<td width=\"149\">Library<\/td>\n<\/tr>\n<tr>\n<td width=\"159\">10 mPa<\/td>\n<td width=\"149\">50<\/td>\n<td width=\"149\">Normal conversation<\/td>\n<td rowspan=\"2\" width=\"170\">Calm<\/td>\n<\/tr>\n<tr>\n<td width=\"159\"><\/td>\n<td width=\"149\">60<\/td>\n<td width=\"149\">Office<\/td>\n<\/tr>\n<tr>\n<td width=\"159\">100 mPa<\/td>\n<td width=\"149\">70<\/td>\n<td width=\"149\">Car transit<\/td>\n<td rowspan=\"2\" width=\"170\">loud<\/td>\n<\/tr>\n<tr>\n<td width=\"159\"><\/td>\n<td width=\"149\">80<\/td>\n<td width=\"149\">Traffic<\/td>\n<\/tr>\n<tr>\n<td width=\"159\">1 Pa<\/td>\n<td width=\"149\">90<\/td>\n<td width=\"149\">Assembly line<\/td>\n<td rowspan=\"3\" width=\"170\">Very loud<\/td>\n<\/tr>\n<tr>\n<td width=\"159\"><\/td>\n<td width=\"149\">100<\/td>\n<td width=\"149\">Discotheque<\/td>\n<\/tr>\n<tr>\n<td width=\"159\">10 Pa<\/td>\n<td width=\"149\">110<\/td>\n<td width=\"149\">Pneumatic drill<\/td>\n<\/tr>\n<tr>\n<td width=\"159\">20 Pa<\/td>\n<td width=\"149\">130<\/td>\n<td width=\"149\">Bore<\/td>\n<td width=\"170\">Intolerable \/ pain threshold<\/td>\n<\/tr>\n<tr>\n<td width=\"159\">100 Pa<\/td>\n<td width=\"149\">140-150<\/td>\n<td width=\"149\">Supersonic jet<\/p>\n<p>(at 25 m of distance)<\/td>\n<td width=\"170\">Intolerable \/ eardrum break<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>How can we evaluate the noise?<\/strong><\/p>\n<p>A sound wave is associated with pressure and frequency, so, even human ear reaction is in function with both these two physical quantity. Usually human ear is more sensible with high frequency than low frequency; moreover, people ear in different way between them.<\/p>\n<p>Weighting filter are used to define threshold level of audibility. There are four weighting filters:<\/p>\n<ul>\n<li><strong>A-weighting<\/strong>filters cover the full audio range, 20 Hz to 20 kHz, the filter &#8216;shape&#8217; is similar to the response of the human ear at the lower sound levels. The preferred convention is to write LA\u00a0= x dB, however dBA and dB(A) are often used, as are\u00a0LAeq,\u00a0LAmax<\/li>\n<li><strong>B-weighting,<\/strong> no longer in common use, was initially developed to cover the mid-range\u00a0loudness scale. It was more &#8216;critical&#8217; of lower frequencies than the A-weighting network which probably accounts for it&#8217;s use by the motor industry for many years after it&#8217;s decline in general popularity.<\/li>\n<li><strong>C-weighting<\/strong>is a standard frequency weighting for sound level meters, commonly used for high level measurements and\u00a0peak sound pressure levels. Approximately follows the 100\u00a0phon\u00a0curve &#8211; also written as dB(C) or dBC. The A-weighting curve is used extensively for general purpose noise measurements but the C-weighting correlates better with the human response to high noise levels.<\/li>\n<li><strong>D-weighting<\/strong>: a sound level meter frequency weighting developed for measuring aircraft noise especially non-bypass military engines. No longer in common use since IEC 61672 2003. More recent ISO standards recommend\u00a0A-weighting\u00a0for commercial aircraft noise.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Noise is an acoustic disturbance effect, natural or artificial, that have a negative effect with listener\u2019s activity. Parameters to describe the noise are: Sound pressure: is the difference between the\u00a0pressure\u00a0caused by a\u00a0sound wave\u00a0and the\u00a0ambient pressure\u00a0of the\u00a0medium the sound wave is passing through. it\u00a0is measured in\u00a0Pascal [Pa]. Frequency: the number of times that a\u00a0periodic\u00a0function or vibration [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":73292,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[37],"tags":[],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v21.0 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>What is the noise? | Scantec<\/title>\n<meta name=\"description\" content=\"Noise is an acoustic disturbance effect, natural or artificial, that have a negative effect with listener\u2019s activity. Sound pressure: is the difference between the pressure caused by a sound wave and the\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"What is the noise? | Scantec\" \/>\n<meta property=\"og:description\" content=\"Noise is an acoustic disturbance effect, natural or artificial, that have a negative effect with listener\u2019s activity. Sound pressure: is the difference between the pressure caused by a sound wave and the\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/\" \/>\n<meta property=\"og:site_name\" content=\"Scantec\" \/>\n<meta property=\"article:published_time\" content=\"2019-04-18T13:19:27+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2019-04-18T13:34:20+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.scantec.it\/en\/wp-content\/uploads\/sites\/2\/2019\/04\/shutterstock_297468155-1024x537.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1024\" \/>\n\t<meta property=\"og:image:height\" content=\"537\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/\"},\"author\":{\"name\":\"admin\",\"@id\":\"https:\/\/www.scantec.it\/en\/#\/schema\/person\/74c32bcea8e1a2b1107bd56ea68f2a72\"},\"headline\":\"What is the noise?\",\"datePublished\":\"2019-04-18T13:19:27+00:00\",\"dateModified\":\"2019-04-18T13:34:20+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/\"},\"wordCount\":452,\"publisher\":{\"@id\":\"https:\/\/www.scantec.it\/en\/#organization\"},\"articleSection\":[\"Noise and Vibration\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/\",\"url\":\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/\",\"name\":\"What is the noise? | Scantec\",\"isPartOf\":{\"@id\":\"https:\/\/www.scantec.it\/en\/#website\"},\"datePublished\":\"2019-04-18T13:19:27+00:00\",\"dateModified\":\"2019-04-18T13:34:20+00:00\",\"description\":\"Noise is an acoustic disturbance effect, natural or artificial, that have a negative effect with listener\u2019s activity. Sound pressure: is the difference between the pressure caused by a sound wave and the\",\"breadcrumb\":{\"@id\":\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.scantec.it\/en\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"What is the noise?\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.scantec.it\/en\/#website\",\"url\":\"https:\/\/www.scantec.it\/en\/\",\"name\":\"Scantec\",\"description\":\"Scantec offers a global service in the field of controls aimed at increasing safety and energy savings in industry and construction\",\"publisher\":{\"@id\":\"https:\/\/www.scantec.it\/en\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.scantec.it\/en\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.scantec.it\/en\/#organization\",\"name\":\"Scantec\",\"url\":\"https:\/\/www.scantec.it\/en\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.scantec.it\/en\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.scantec.it\/en\/wp-content\/uploads\/sites\/2\/2017\/09\/scantec.png\",\"contentUrl\":\"https:\/\/www.scantec.it\/en\/wp-content\/uploads\/sites\/2\/2017\/09\/scantec.png\",\"width\":180,\"height\":30,\"caption\":\"Scantec\"},\"image\":{\"@id\":\"https:\/\/www.scantec.it\/en\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.scantec.it\/en\/#\/schema\/person\/74c32bcea8e1a2b1107bd56ea68f2a72\",\"name\":\"admin\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"What is the noise? | Scantec","description":"Noise is an acoustic disturbance effect, natural or artificial, that have a negative effect with listener\u2019s activity. Sound pressure: is the difference between the pressure caused by a sound wave and the","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/","og_locale":"en_US","og_type":"article","og_title":"What is the noise? | Scantec","og_description":"Noise is an acoustic disturbance effect, natural or artificial, that have a negative effect with listener\u2019s activity. Sound pressure: is the difference between the pressure caused by a sound wave and the","og_url":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/","og_site_name":"Scantec","article_published_time":"2019-04-18T13:19:27+00:00","article_modified_time":"2019-04-18T13:34:20+00:00","og_image":[{"width":1024,"height":537,"url":"https:\/\/www.scantec.it\/en\/wp-content\/uploads\/sites\/2\/2019\/04\/shutterstock_297468155-1024x537.jpg","type":"image\/jpeg"}],"author":"admin","twitter_card":"summary_large_image","twitter_misc":{"Written by":"admin","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/#article","isPartOf":{"@id":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/"},"author":{"name":"admin","@id":"https:\/\/www.scantec.it\/en\/#\/schema\/person\/74c32bcea8e1a2b1107bd56ea68f2a72"},"headline":"What is the noise?","datePublished":"2019-04-18T13:19:27+00:00","dateModified":"2019-04-18T13:34:20+00:00","mainEntityOfPage":{"@id":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/"},"wordCount":452,"publisher":{"@id":"https:\/\/www.scantec.it\/en\/#organization"},"articleSection":["Noise and Vibration"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/","url":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/","name":"What is the noise? | Scantec","isPartOf":{"@id":"https:\/\/www.scantec.it\/en\/#website"},"datePublished":"2019-04-18T13:19:27+00:00","dateModified":"2019-04-18T13:34:20+00:00","description":"Noise is an acoustic disturbance effect, natural or artificial, that have a negative effect with listener\u2019s activity. Sound pressure: is the difference between the pressure caused by a sound wave and the","breadcrumb":{"@id":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.scantec.it\/en\/noise-and-vibration\/what-is-the-noise\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.scantec.it\/en\/"},{"@type":"ListItem","position":2,"name":"What is the noise?"}]},{"@type":"WebSite","@id":"https:\/\/www.scantec.it\/en\/#website","url":"https:\/\/www.scantec.it\/en\/","name":"Scantec","description":"Scantec offers a global service in the field of controls aimed at increasing safety and energy savings in industry and construction","publisher":{"@id":"https:\/\/www.scantec.it\/en\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.scantec.it\/en\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.scantec.it\/en\/#organization","name":"Scantec","url":"https:\/\/www.scantec.it\/en\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.scantec.it\/en\/#\/schema\/logo\/image\/","url":"https:\/\/www.scantec.it\/en\/wp-content\/uploads\/sites\/2\/2017\/09\/scantec.png","contentUrl":"https:\/\/www.scantec.it\/en\/wp-content\/uploads\/sites\/2\/2017\/09\/scantec.png","width":180,"height":30,"caption":"Scantec"},"image":{"@id":"https:\/\/www.scantec.it\/en\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/www.scantec.it\/en\/#\/schema\/person\/74c32bcea8e1a2b1107bd56ea68f2a72","name":"admin"}]}},"_links":{"self":[{"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/posts\/73294"}],"collection":[{"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/comments?post=73294"}],"version-history":[{"count":4,"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/posts\/73294\/revisions"}],"predecessor-version":[{"id":73314,"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/posts\/73294\/revisions\/73314"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/media\/73292"}],"wp:attachment":[{"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/media?parent=73294"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/categories?post=73294"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.scantec.it\/en\/wp-json\/wp\/v2\/tags?post=73294"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}