<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0121-750X</journal-id>
<journal-title><![CDATA[Ingeniería]]></journal-title>
<abbrev-journal-title><![CDATA[ing.]]></abbrev-journal-title>
<issn>0121-750X</issn>
<publisher>
<publisher-name><![CDATA[Universidad Distrital Francisco José de Caldas]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0121-750X2022000100204</article-id>
<article-id pub-id-type="doi">10.14483/23448393.18466</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Evaluation of the Accuracy of the Sound Field Separation Method under Variations in the Location of the Sampling Points]]></article-title>
<article-title xml:lang="es"><![CDATA[Evaluación de la precisión del método de separación de campos sonoros bajo variaciones en la ubicación de los puntos de muestreo]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[López-Mejía]]></surname>
<given-names><![CDATA[Sebastián]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Piedrahita-Montes]]></surname>
<given-names><![CDATA[Andrés Felipe]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad de San Buenaventura Facultad de Ingenierías ]]></institution>
<addr-line><![CDATA[Medellín ]]></addr-line>
<country>Colombia</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad de San Buenaventura  ]]></institution>
<addr-line><![CDATA[Medellín ]]></addr-line>
<country>Colombia</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>04</month>
<year>2022</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>04</month>
<year>2022</year>
</pub-date>
<volume>27</volume>
<numero>1</numero>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_arttext&amp;pid=S0121-750X2022000100204&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_abstract&amp;pid=S0121-750X2022000100204&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_pdf&amp;pid=S0121-750X2022000100204&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract  Context:  Measuring the directivity characteristics and the frequency response of acoustic sources is a difficult process, as the dimensions and boundary conditions of the testing rooms used could constrain the measurement procedure. The testing room should guarantee a free-field condition, which is usually satisfied by using big acoustic absorbers with fibrous materials with high absorption coefficients. Ho wever, standing wave patterns can be easily developed due to the frequency range exciting the testing room.  Method:  The sound field separation method can isolate the radiated field of an acoustic source by sampling the sound field around it over two holographic spheres. The coordinates of the sampling points are used in a set of equations, whose solution can estimate the radiated field. In this paper, the effect of the variability on the actual positions of these sampling points is investigated.  Results:  Two numerical simulations with and without external sources outside the holographic spheres were performed. In all simulations, variations in the radial position of the sampling points were induced, and the relative reconstruction error, the directivity index, and the frequency response were studied. The results indicate that, for estimating the directivity of low-frequency acoustic sources, regardless of the presence of external sources, radial positioning of the sensors does not have to be exact to obtain an accurate reconstruction.  Conclusions:  This study suggests that, in the experimental characterization in conventional testing rooms of the radiated field from acoustic sources whose main frequency region corresponds to low frequencies, e.g. subwoofers, the SFS method could be used, thus obtaining high accuracy in the estimation of the directivity of the source.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen  Contexto:  La medición de las características de directividad y de respuesta en frecuencia de fuentes acústicas es un procedimiento difícil debido a que las dimensiones y condiciones de frontera del recinto dentro del cual se hace el ensayo podrían limitar el procedimiento de medición. El recinto de ensayo debería garantizar condición de campo libre, lo cual se consigue usualmente con absortores acústicos de gran dimensión hechos de materiales fibrosos con altos coeficientes de absorción. Sin embargo, se pueden desarrollar con facilidad patrones de ondas estacionarias debido al rango de frecuencia que hace vibrar el recinto de ensayo.  Método:  El método de separación de campos sonoros puede aislar el campo irradiado por una fuente acústica a través del muestreo del campo sonoro alrededor de ella en dos esferas holográficas. Las coordenadas de los puntos de muestreo se usan en un conjunto de ecuaciones cuya solución permite estimar el campo irradiado. En este artículo se investiga el efecto de la variación en las posiciones reales de los puntos de muestreo.  Resultados:  Se hicieron dos simulaciones numéricas fuera de las esferas holográficas, una sin fuentes externas y otra con fuentes externas. En todas las simulaciones se indujeron variaciones en las posiciones radiales de los puntos de muestreo y se estimaron el error relativo de reconstrucción, el índice de directividad y la respuesta de frecuencia. Los resultados indican que, para estimar el índice de directividad de fuentes acústicas de bajas frecuencias, independientemente de la presencia de fuentes externas, la posición radial de los sensores no tiene que ser exacta para lograr una estimación precisa.  Conclusiones:  Este estudio sugiere que, en la caracterización experimental en recintos convencionales del campo irradiado por fuentes acústicas cuyo rango de frecuencia predominante es el de bajas frecuencias, por ejemplo, subwoofers, el método de separación de campos puede ser usado, obteniendo resultados de alta precisión en la estimación de la directividad de la fuente.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[sound field separation]]></kwd>
<kwd lng="en"><![CDATA[acoustic radiation]]></kwd>
<kwd lng="en"><![CDATA[spherical harmonics.]]></kwd>
<kwd lng="es"><![CDATA[separación de campos sonoros]]></kwd>
<kwd lng="es"><![CDATA[radiación acústica]]></kwd>
<kwd lng="es"><![CDATA[armónicos esféricos.]]></kwd>
</kwd-group>
</article-meta>
</front><back>
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