<p class="MsoBodyText" style="mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">This document specifies a method for estimating the loudness and loudness level of both stationary and time-varying sounds as perceived by otologically normal adult listeners under specific listening conditions. The sounds may be recorded using a single microphone, using a head and torso simulator, or, for sounds presented via earphones, the electrical signal delivered to the earphones may be used.</span></p>
<p class="MsoBodyText" style="mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">The method is based on the Moore-Glasberg-Schlittenlacher algorithm.</span></p>
<p class="Note" style="tab-stops: 19.85pt 39.7pt 48.25pt 59.55pt 79.4pt 99.25pt 119.05pt 138.9pt 158.75pt 178.6pt 7.0cm; mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">NOTE 1<span style="mso-tab-count: 1;"> </span>Users who wish to study the details of the calculation method can review or implement the source code which is entirely informative and provided with the standard for the convenience of the user.</span></p>
<p class="MsoBodyText" style="mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">This method can be applied to any sounds, including tones, broadband noises, complex sounds with sharp line spectral components, musical sounds, speech, and impact sounds such as gunshots and sonic booms.</span></p>
<p class="MsoBodyText" style="mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">Calculation of a single value for the overall loudness over the entire period of a time-varying signal lasting more than 5 s is outside the scope of this document.</span></p>
<p class="Note" style="tab-stops: 19.85pt 39.7pt 48.25pt 59.55pt 79.4pt 99.25pt 119.05pt 138.9pt 158.75pt 178.6pt 7.0cm; mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">NOTE 2<span style="mso-tab-count: 1;"> </span>It has been shown that, for steady tones, this method provides a good match to the contours of equal loudness level as defined in <span class="stdpublisher"><span style="color: black; mso-color-alt: windowtext;">ISO</span></span> <span class="stddocNumber"><span style="color: black; mso-color-alt: windowtext;">226</span></span>:<span class="stdyear"><span style="color: black; mso-color-alt: windowtext;">2003</span></span><sup>[<span class="citebib"><span style="color: black; mso-color-alt: windowtext;">18</span></span>]</sup> and the reference threshold of hearing as defined in <span class="stdpublisher"><span style="color: black; mso-color-alt: windowtext;">ISO</span></span> <span class="stddocNumber"><span style="color: black; mso-color-alt: windowtext;">389</span></span>-<span class="stddocPartNumber"><span style="color: black; mso-color-alt: windowtext;">7</span></span>:<span class="stdyear"><span style="color: black; mso-color-alt: windowtext;">2019</span></span><sup>[<span class="citebib"><span style="color: black; mso-color-alt: windowtext;">19</span></span>]</sup>.</span></p>
Registration number (WIID)
90816
Scope
<p class="MsoBodyText" style="mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">This document specifies a method for estimating the loudness and loudness level of both stationary and time-varying sounds as perceived by otologically normal adult listeners under specific listening conditions. The sounds may be recorded using a single microphone, using a head and torso simulator, or, for sounds presented via earphones, the electrical signal delivered to the earphones may be used.</span></p>
<p class="MsoBodyText" style="mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">The method is based on the Moore-Glasberg-Schlittenlacher algorithm.</span></p>
<p class="Note" style="tab-stops: 19.85pt 39.7pt 48.25pt 59.55pt 79.4pt 99.25pt 119.05pt 138.9pt 158.75pt 178.6pt 7.0cm; mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">NOTE 1<span style="mso-tab-count: 1;"> </span>Users who wish to study the details of the calculation method can review or implement the source code which is entirely informative and provided with the standard for the convenience of the user.</span></p>
<p class="MsoBodyText" style="mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">This method can be applied to any sounds, including tones, broadband noises, complex sounds with sharp line spectral components, musical sounds, speech, and impact sounds such as gunshots and sonic booms.</span></p>
<p class="MsoBodyText" style="mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">Calculation of a single value for the overall loudness over the entire period of a time-varying signal lasting more than 5 s is outside the scope of this document.</span></p>
<p class="Note" style="tab-stops: 19.85pt 39.7pt 48.25pt 59.55pt 79.4pt 99.25pt 119.05pt 138.9pt 158.75pt 178.6pt 7.0cm; mso-layout-grid-align: none; text-autospace: none;"><span lang="EN-GB" style="mso-bidi-font-size: 12.0pt;">NOTE 2<span style="mso-tab-count: 1;"> </span>It has been shown that, for steady tones, this method provides a good match to the contours of equal loudness level as defined in <span class="stdpublisher"><span style="color: black; mso-color-alt: windowtext;">ISO</span></span> <span class="stddocNumber"><span style="color: black; mso-color-alt: windowtext;">226</span></span>:<span class="stdyear"><span style="color: black; mso-color-alt: windowtext;">2003</span></span><sup>[<span class="citebib"><span style="color: black; mso-color-alt: windowtext;">18</span></span>]</sup> and the reference threshold of hearing as defined in <span class="stdpublisher"><span style="color: black; mso-color-alt: windowtext;">ISO</span></span> <span class="stddocNumber"><span style="color: black; mso-color-alt: windowtext;">389</span></span>-<span class="stddocPartNumber"><span style="color: black; mso-color-alt: windowtext;">7</span></span>:<span class="stdyear"><span style="color: black; mso-color-alt: windowtext;">2019</span></span><sup>[<span class="citebib"><span style="color: black; mso-color-alt: windowtext;">19</span></span>]</sup>.</span></p>
