The Acoustics of the Choir in Spanish Cathedrals

One of the most significant enclosures in worship spaces is that of the choir. Generally, from a historical point of view, the choir is a semi-enclosed and privileged area reserved for the clergy, whose position and configuration gives it a private character. Regarding the generation and transformation of ecclesial interior spaces, the choir commands a role of the first magnitude. Its shape and location produce, on occasions, major modifications that significantly affect the acoustics of these indoor spaces. In the case of Spanish cathedrals, whose design responds to the so-called “Spanish type”, the central position of the choir, enclosed by high stonework walls on three of its sides and with numerous wooden stalls inside, breaks up the space in the main nave, thereby generating other new spaces, such as the trascoro. The aim of this work was to analyse the acoustic evolution of the choir as one of the main elements that configure the sound space of Spanish cathedrals. By means of in situ measurements and simulation models, the main acoustic parameters were evaluated, both in their current state and in their original configurations that have since disappeared. This analysis enabled the various acoustic conditions existing between the choir itself and the area of the faithful to be verified, and the significant improvement of the acoustic quality in the choir space to become apparent. The effect on the acoustic parameters is highly significant, with slight differences in the choir, where the values are appropriate for Gregorian chants, and suitable intelligibility of sung text. High values are also obtained in the area of the faithful, which lacked specific acoustic requirements at the time of construction

Electrospinning de poliesteramidas biodegradables

L’electrospinning és una técnica que permet obtener fibres de diàmetres de nanometres fins a micres. Consteix en aplicar una diferencia de potencial en una gota de dissolució de polímer que flueix al llarg del injector. En aquest projecte s’ha realitzat un estudi exhaustiu sobre la formació de fibres a partir de les poliesteramides PADAS i PGBGS. S’ha investigat la relació entre les característiques de les fibres obtingudes amb el dissolvent fet servir, el fluxe d’injecció, la distancia injector-col.lector i la concentració polímer/dissolvent

On the efficiency of impact sound insulation systems on prefabricated lightweight floor and on standard homogeneous base-floor

Considering the impact noise as a major social issue in many countries, extensive work have been developed aimed at reducing the noise level in dwellings. Laboratory tests were carried out to investigate the acoustic performance of same constructive proposals, arranged to reduce the impact sound transmission. According to this study, acoustic performance of both types of floors differs significantly, with a difference of up to four times that of the effect of floating floor system on a homogeneous floor in some cases. The conclusions can help to determine the proposal of best suitable constructive solutions in accordance with legal regulations

Acoustical influence of different locations of the choir in the cathedral of Granada from a subjective and objective overview

The choir is a space that greatly influences the design and architectural configuration of a cathedral. Cultural influence, the reform of the liturgy and agreements reached during ecclesiastical councils in the last centuries have promoted a relocation of this space. Since its origins, it has been a privileged and reserved enclosure, providing a private character. This space is reserved for the clergy for prayer, preaching, or chant, promoting churches as places where music can be heard. The Renaissance cathedral of Granada in Spain is one of the most important historic religious spaces in southern Europe. Over time, the choir was moved up from the central nave to the back of the presbytery to be finally distributed inside the cathedral. Virtual modelling using geometrical acoustic prediction is a very helpful tool to investigate these choir locations in the acoustic behaviour of the cathedral. Hence, based on experimental acoustic measurements carried out previously, sound space reconstruction was recreated virtually. The creation of a virtual model of its sound field led to the implementation of the three main documented changes. In this paper, the role of the choir within the liturgy was considered in terms of acoustics and the acoustical performance of the evolution of various interventions was analysed. The impact of the relocation of choral space is evaluated from a perspective that analyses the relationship between subjective qualities and the acoustic parameters measured. In addition, the acoustical suitability of the cathedral in terms of the performance of different music motifs is also considered. Therefore, a comparative analysis in terms of temporal design, incorporating the study of early reflections together with the type of music is addressed to investigate the influence on the acoustical performance of the cathedral

On the assessment of the multiplicity of spaces in the acoustic environment of cathedrals: the case of the cathedral of Seville

Depending on the type of configuration to be adopted there are multiple forms of occupation of a cathedral which can significantly influence the acoustic environment. As a result, several activities with different acoustic requirements, including preaching and the musical performance of a song or piece can coexist during the same ceremony. Therefore, the requirements needed to achieve suitable acoustic conditions may vary depending on the type of configuration. This article presents the development of the multiple spaces inside the cathedral of Seville, the largest Gothic church in the world. The aim is to evaluate the acoustic environment of the cathedral, which has an exceptional multifunctional character, in terms of the different configurations generated inside for concerts and other unique ceremonies, as well as the varied arrangement of the sound sources to meet the requirements of these events. The in situ acoustic measurement carried out in the cathedral enabled the assessment of the current acoustic conditions. In addition, the use of virtual simulation tools made it possible to recover the sound of past times and to establish its potential in future intervention projects. The evaluation of various configurations established the effects of the occupation, of decoration in the acoustic environment, and of different choral and instrumental musical motifs. This analysis was carried out taking into consideration the objective acoustic parameters contained in ISO 3382 and a subjective approach to the temporal and spatial factors. According to this analysis in a large multifunctional building such as the cathedral of Seville there is no general preference for a specific music motif given that the subjective perception of the sound field depends on the type of configuration, while occupation varies depending on the purpose of the event

Virtual reconstruction of indoor acoustics in cathedrals: the case of the cathedral of Granada

Virtual acoustics provides a highly useful tool for the investigation into the influence that spatial transformations may exert on indoor acoustics of cathedrals, which are remarkable spaces due to their heritage value, complexity and multifunctional character. The spatial organization of cathedrals is primarily governed by the location of the choir, which represents the main musical expression. Following various reforms, certain European cathedrals undertook a relocation of the choir stalls from their original position. The Cathedral of Granada is a highly significant case. Since its original construction, three major changes have occurred due to the relocation of the choir. In this article, simulation of indoor acoustics is employed to recover the soundfield in each of these three configurations. An extensive analysis compares the results of the main acoustic parameters in each of the virtual reconstruction models. Consequently, acoustic models are created and then calibrated based on a campaign of onsite measurements

Electrospinning de poliesteramidas biodegradables

L’electrospinning és una técnica que permet obtener fibres de diàmetres de nanometres fins a micres. Consteix en aplicar una diferencia de potencial en una gota de dissolució de polímer que flueix al llarg del injector. En aquest projecte s’ha realitzat un estudi exhaustiu sobre la formació de fibres a partir de les poliesteramides PADAS i PGBGS. S’ha investigat la relació entre les característiques de les fibres obtingudes amb el dissolvent fet servir, el fluxe d’injecció, la distancia injector-col.lector i la concentració polímer/dissolvent

Acoustical retrofit of existing residential buildings: Requirements and recommendations for sound insulation between dwellings in Europe and other countries worldwide

Exposure to noise is proven to have important repercussions on human comfort and health conditions. In recent decades, efforts to increase awareness among users have focused on highlighting the benefits of an appropriate acoustic indoor environment. In addition, given the significant increase in complaints about noise, the control, reduction, and limitation of sound transmission have become important issues to be considered in acoustic retrofit work in buildings. Much of the housing stock was built in a period characterized by the limitation or absence of standards, and renovation interventions should be geared towards existing buildings. However, despite the major potential to improve quality of life, only a handful of countries consider old buildings in their national Building Codes and regulations. The main aim of this work is to develop a comparative study of the acoustic requirements for indoor sound insulation between dwellings of existing buildings established in current building regulations around the world. The analysis of the documents concludes that the usual difference between requirements for new and existing buildings is 5 dB, both for airborne sound insulation and impact sound insulation. To this end, this paper provides the basis for discussion regarding future cooperation for the optimization of acoustic regulations for old buildings

Is indoor overheating an upcoming risk in southern Spain social housing stocks? Predictive assessment under a climate change scenario

Beyond thermal comfort, the future outlook of climate change poses a challenge for the health of the most vulnerable inhabitants of the existing residential stock. In southern Spain specifically there is extensive social housing stock that is obsolete from an energy perspective and occupied by an aging population with economic constraints for the use of energy. The main aim of this work is to evaluate the possible comfort risks in terms of overheating following the different criteria established by the Chartered Institution of Building Services Engineers (CIBSE), both under current conditions and in a climate change scenario. For this purpose, a parametric simulation model was developed to reliably evaluate the category of linear-type social housing from the postwar period, a total of more than 42,000 dwellings. The results show that around 38% of the evaluated cases are already at risk of overheating as they fail to meet two of the three adaptive criteria set in TM52. By 2050 this figure will be almost 100%. In addition, it is expected that global warming will result in an increase of up to 40% in the percentage of Hours of Exceedance

Influence of the critical parameters on the density estimate of some fatty acids by the Rackett's method

9 páginas, 3 figuras, 3 tablas.[ES] En este trabajo se realiza un estudio comparativo de las propiedades críticas temperatura y presión en los ácidos grasos palmítico, esteárico y oléico, proporcionadas por diferentes fuentes bibliográficas. Estas propiedades se utilizan en la ecuación de Rackett para estimar la densidad de las sustancias puras. Se describen y emplean los métodos más comúnmente aplicados en estos casos para estimar dichas propiedades críticas. Se selecciona un conjunto de valores de propiedades críticas para aplicarlas en la estimación de la densidad por la ecuación de Rackett. Se proponen los valores de las propiedades críticas con los que se obtiene una mejor estimación de la densidad, cuando se compara con resultados experimentales. Se demuestra que la selección de las propiedades críticas influye de forma decisiva en la estimación de propiedades físicas mediante la ecuación de Rackett.[EN] In this work a comparative study is carried out of the critical properties of temperature and pressure applied for the palmitic, stearic and oleic fatty acids, provided by different bibliographical sources. These properties are used in the Rackett's equation to estimate the density of the pure substances. The most commonly employed methods are described and applied in these cases to estimate these critical properties. A group of values of critical properties is selected to estimate the density using the Rackett's equation. The values of the critical properties that give a better estimation of the density, according to Rackett's equation, when compared with the experimental results are proposed. It is demonstrated that the selection of the critical properties influences in a decisive way in the estimation of physical properties by means of the Rackett's equation.Los autores hacen constar su agradecimiento a: La Comisión Interministerial de Ciencia y Tecnología, por la ayuda recibida para la realización de este trabajo: ALI 95 0517. Al Instituto de Cooperación Iberoamericana (ICI), por la beca proporcionada para la realización de la Tesis Doctoral.Peer reviewe