{"id":280668,"date":"2024-10-19T18:57:28","date_gmt":"2024-10-19T18:57:28","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/bs-en-iso-389-41999\/"},"modified":"2024-10-25T15:34:12","modified_gmt":"2024-10-25T15:34:12","slug":"bs-en-iso-389-41999","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/bsi\/bs-en-iso-389-41999\/","title":{"rendered":"BS EN ISO 389-4:1999"},"content":{"rendered":"<p>This part of ISO&nbsp;389 specifies reference levels for narrow-band masking noise presented by air conduction from an earphone in pure-tone audiometry. The data are given in terms of levels to be added to the reference equivalent threshold sound pressure levels for the corresponding pure-tone frequencies as specified in ISO&nbsp;389:1991 or ISO&nbsp;389-2, respectively, when the masking earphone is placed on the appropriate acoustic coupler, ear simulator or artificial ear.<\/p>\n<p>Data are given for noise bandwidths of one-third and one-half octaves.<\/p>\n<blockquote>\n<p>NOTE&nbsp;1 Some notes on the derivation of the reference levels are given in annex&nbsp;A.<\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p><b>Acoustics. Reference zero for the calibration of audiometric equipment &#8211; Reference levels for narrow-band masking noise<\/b><\/p>\n<table class=\"shortdes-table\" style=\"width: 100%\" border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td>Published By<\/td>\n<td>Publication Date<\/td>\n<td>Number of Pages<\/td>\n<\/tr>\n<tr>\n<td><a href=\"https:\/\/pdfstandards.shop\/product-category\/publishers\/bsi\/\"><b>BSI<\/b><\/a><\/td>\n<td>1999<\/td>\n<td>16<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":280671,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[136,2641],"product_tag":[],"class_list":{"0":"post-280668","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-11-040-01","7":"product_cat-bsi","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/280668","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/280671"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=280668"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=280668"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=280668"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}