International Symposium on Room Acoustics
ISRA 2007 SEVILLA
 
Seville, 10 - 12 September 2007
 
Satellite Symposium of the 19th International Congress on Acoustics

P01

The sonic space in architectural design. How architects and urban designers should take sound as a design tool for creating space in architecture and the city

PACS: 43.55.Fw

Rodríguez-Manzo, Fausto E.¹; Garay, Elisa²

¹Laboratorio de Análisis y Diseño Acústico; Departamento de Procesos y Técnicas, CyAD UAM-A; Av. San Pablo 180 Edif. H PB, 02200 México D.F, México; rfme_at_or_arroba_correo.azc.uam.mx
²Programa de Posgrado en Diseño, CyAD UAM-A; Av. San Pablo 180 D-101, 02200 México D.F, México; elisagaray_at_or_arroba_gmail.com

Usually sound has been the field of least interest in architectural design. Architects and urban designers have not developed forms or methods to approach sound from the architectural and urban design point of view, there are very few ideas about how to take on board sound as a component of the architectural and the urban space. Some proposals about soundscape for the city and the landscape have been developed, but this approach relates more with an artistic thinking than an architectural one. This is a field more in the way of conceiving a space as a music composition. Probably we can take it as a basis but the need of taking sound into account as an essential component of the architectural and the urban space has to develop new design tools for conceiving space in architecture and the city. The question is, how architects and urban designers should take sound as part of their design methods to use it as a tool for their daily design tasks? This is the kind of research that the authors are developing and this paper offers a proposal about this design matter and shows an analytic approach with some architectural and urban space examples.

Investigation of the noise attenuation from outdoor to indoor of typical residential buildings in China

PACS: 43.55.Rg

Xie,Hui

School of Architecture, University of Sheffield, UK; yanshencun_at_or_arroba_hotmail.com

Nowadays, more and more people in China began to suffer from the noise pollution due to the rapid urban development. This study outlines the result of noise attenuation investigations from outdoor to indoor at a typical roadside building in China. Two sound meters were placed in the centre of the outdoor balcony and the indoor living room of the building, respectively. They could simultaneously auto-record the sound level of outdoors and indoors at every second. Then, 23105 group data was obtained by the field measurement in the morning, afternoon and night, which was 9:30am- 12:00 am, 2:30pm- 5:30pm and 1:00am- 3:30am. After analyzed by the statistic software SPSS 13.0, three models in different time were listed. In the models, the dependent factor was the outdoor-indoor relative attenuation, the independent factors was the outdoor sound level. Ten Curve-fitting methods, including linear, quadratic, compound, growth, logarithmic, cubic, S, exponential, inverse, power equations, were used to determine the correlation between dependent and independent factors. After compared the R Square of each equation, it is concluded that the quadratic equation is the best model to describe the outdoor-indoor noise attenuation with R2>0.97 at all the three different time.

Modal energy density influence on in situ sound reduction index measurements

PACS: 43.55.Br; 43.55.Rg.

Rolón, Sebastián; Montoya, Adrián; Pesse, Ricardo

Acoustic Research Center, University of Santiago de Chile, Av. Ecuador 54, Santiago, Chile; scebastian.rolon_at_or_arroba_gmail.com, adrian.montoya.leyton_at_or_arroba_gmail.com, opesse_at_or_arroba_usach.cl

Sound insulation fulfillments inspection on building constructions and industrial noise control is fundamental for the advances on noise environmental laws. The traditional pressure-based methods of measuring sound reduction indexes require reverberant rooms for their implementation, and the real behavior of these rooms at low frequencies is not exactly as the diffuse field model assume. Therefore, there is tendency to overestimate the sound insulation of a partition on those frequencies. Transmission loss measurements on two different situations according to ISO 140-4 were done, and through a finite element method, the low-frequency modal behavior of the rooms was analyzed. Considering the receiver room modal density on sound transmission loss measurements increased the method's precision by getting closer to a real diffuse field case. The results for each situation were verified using the sound intensity method according to ISO 15186-2, which due to its characteristics does not need this consideration.

Acoustics of Peruvian catholic cathedrals of the colonial era: an experimental study

PACS: 43.55.Gx

Jiménez Dianderas, Carlos R.¹; Recuero López, Manuel²

¹Pontificia Universidad Católica del Perú, CIAC-Departamento de Arquitectura, Avenida Universitaria 1801, Lima 32, Perú; cjimene_at_or_arroba_pucp.edu.pe
²Universidad Politécnica de Madrid, INSIA, Carretera de Valencia Km.7, 28031 Madrid, España; manuel.recuero_at_or_arroba_upm.es

This paper reports the analysis of the results of an acoustic survey carried out on four Catholic Cathedrals in some cities of Peru, built during the colonial era through centuries XVI to XVII. The study is performed taking into account both room-average values and individual position values of many acoustical parameters measured according to ISO 3382. Effects among architectural characteristics (room volume, surface areas, total absorbing area) and some objective acoustical parameters (reverberation time, early decay time, clarity, definition, center time) are investigated.

Acoustics of Mudejar-Gothic churches

PACS: 43.55.Br, 43.55.Gx

S. Girón, T. Zamarreño, M. Galindo.

Dept. Física Aplicada II, Univ. de Sevilla, E.T.S. Arquitectura (IUCC); Avda. R. Mercedes 2, 41012-Sevilla, Spain; sgiron_at_or_arroba_us.es; mgalindo_at_or_arroba_us.es; teofilo_at_or_arroba_us.es

This paper summarizes a complete description of the acoustical behaviour of 12 Mudejar-Gothic churches located in the city of Seville in southern Spain. The study covers objective monaural parameters based both on acoustic energy and intelligibility descriptors derived from the modulation transfer function. Impulse response analysis through a maximum-length sequence measurement system has been used to produce octave-band filtered results. The parameters have been spectrally averaged in accordance with the most extended criteria in auditoria in order to consider acoustic quality. Their average values have been studied as a function of source-receiver distance within the churches and they have been interpreted through the μ model. This semi-empirical model supposes that early reflected energy suffers an attenuation, with respect to the classic diffuse theory, that is dependent on source-receiver distance and on a coefficient μ deduced by non-linear regression in order to maximise the correlation between the experimental values of C₈₀ parameter in the churches.

Predicted and measured acoustic parameters in churches

PACS: 43.55.Br, 43.55.Gx

M. Galindo, T. Zamarreño, S. Girón.

Dept. Física Aplicada II, Univ. de Sevilla, E.T.S. Arquitectura (IUCC); Avda. R. Mercedes 2, 41012-Sevilla, Spain; mgalindo_at_or_arroba_us.es; teofilo_at_or_arroba_us.es; sgiron_at_or_arroba_us.es.

In this paper an analysis of the spatial distribution of room acoustic parameters in three different types of churches of the Iberian Peninsula is presented. This analysis is accomplished by applying the methodology implemented by the authors for a specific typology: the Mudejar-Gothic churches. The three churches, São Roque in Lisbon (Portugal), Santa María Magdalena in the city of Córdoba (Spain) and San Pedro in Priego (Córdoba-Spain), correspond to the Mannerist, Mudejar-Gothic and Baroque architectural styles respectively, and present differences in their typologies, decoration and furniture. The acoustic energy pattern proposed is suitable for taking the singularities of each church into account and for predicting the behaviour of the main room acoustic parameters.

La Philharmonie de Paris concert hall competition, part 2: the competition

PACS: 43.55.Fw

Kahle, Eckhard; Wulfrank, Thomas; Jurkiewicz, Yann; Faillet, Nathalie; Katz, Brian FG

Kahle Acoustics; Avenue Molière 188, 1050 Brussels, Belgium; kahle_at_or_arroba_kahle.be

An international architectural competition was organized for a new 2400 seat concert hall to be constructed on the site of the Parc de la Villette, next to the existing Cité de la Musique. Six teams were invited to participate in the second round of the competition and present their design concepts. As French legislation defines architectural competitions as being design team competitions, it was required for each architect entering the competition to have their own acoustic consultant and theatre planner. The different competition entries are presented and briefly discussed from an architectural, theatre planning and acoustic point of view. Studying the entries shows both similarities and differences in the lines of thought of current architects, theatre planners and acoustic consultants in how to respond to a challenging, innovative architectural and user brief.

Room acoustics simulations using head-related transfer functions of children and adults

PACS: 43.55.Hy

Fels, Janina; Schröder, Dirk; Vorländer, Michael

Institute of Technical Acoustics, RWTH Aachen University; 52056 Aachen, Germany; Janina.Fels_at_or_arroba_akustik.rwth-aachen.de

Today, the evaluation of the acoustic quality of classrooms is mainly based on parameters such as late reverberation and noise level. However, when designing/optimizing classrooms the teaching situation must be considered, too. Especially the speech perception under the influence of deficient noise and reverberation in various classroom types are of high acoustic interest. In addition, the speech perception is heavily affected by different kinds and levels of noise inside the classroom. Thus, the whole binaural room acoustic situation has to be taken into account for a more realistic evaluation. Furthermore, recent investigations have shown that the differences between head-related transfer functions of children and adults are significant and cannot be neglected. In this contribution room acoustic simulations of classrooms are presented and discussed. In order to gain an impression of the room's influences on speech perception, the simulations are carried out with various setups using deficient noise and three different types of receivers (microphone, child, adult).

Relationship between scattering coefficients of walls and diffusion in a room

PACS: 43.55.Br

Hanyu, Toshiki

Nihon University, Narashinodai, Funabashi, 274-8501, Japan; hanyu_at_or_arroba_arch.jcn.nihon-u.ac.jp

The relationship between scattering coefficients of walls and room diffusion was examined. First, using the scattering coefficients of walls and the mean free path in a room, the concepts of equivalent scattering area and average scattering coefficient to express diffusion in a room were introduced. In addition, it was indicated that the time variation of the ratio of specularly reflected sounds to diffused sounds in a whole room.

Acoustical characterization of some classrooms of the University of Extremadura, Spain

PACS: 43.55.Cs

Gómez Escobar, Valentín; Barrigón Morillas, Juan Miguel; Méndez Sierra, Juan Antonio; Vílchez Gómez, Rosendo J., Carmona del Río, Javier.

Universidad de Extremadura; Escuela Politécnica / Departamento de Física Aplicada. Avda. de la Universidad, s/n 10071 Cáceres, España. Tel.: 34 927257195; Fax: 34 927257203; valentin_at_or_arroba_unex.es

Some acoustical parameters were studied for different classrooms of the University of Extremadura, in the campus of Cáceres (Spain). Parameters related with the reverberation time, noise background, sound level and intelligibility were studied. Intelligibility tests were also performed. The results obtained show doubts about the adequate intelligibility of these rooms. Some analysis of the relationship among the different intelligibility parameters studied and the reverberation time were carried out. Reverberation time measure was compared to some recommended values proposed by some authors.

How many point sources are needed to represent strings in auralization?

PACS: 43.55.Ka

Lokki, Tapio

Helsinki University of Technology, Telecommunications Software and Multimedia Laboratory; P.O.Box 5400, FI-02015 TKK, Finland; Tapio.Lokki_at_or_arroba_tkk.fi

An anechoic full symphony orchestra recording is an essential stimulus for auralization studies on concert hall acoustics. Such stimulus material can be achieved by recording instruments one by one in an anechoic chamber. However, for practical reasons the recording of all strings is usually not possible and instead only one or two of each string instrument is recorded. Thus, it raises a question how strings should be represented in auralization so that string sections sound like in a large orchestra. Therefore, auralizations with different number of point sources per each section were made and a listening test was organized to find out perceptual differences. The A/B comparison paradigm was applied and subjects compared differences in perceived number of musicians, spaciousness of auralization, and the overall preference. The results suggest that strings should be modeled with one point source for each musician, but one single recording can be applied in all positions for each section. However, the found differences are quite small and it seems that reasonable auralizations can also be made by representing all strings with only five carefully selected point sources, one for each section.

Effect of orchestra pit arrangement on sound strength in Wroclaw Opera House

PACS: 43.55.Gx

Rudno-Rudziński, Krzysztof

Wrocław University of Technology; Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; krzysztof.rudno-rudzinski_at_or_arroba_pwr.wroc.pl

As part of the recently completed renovation of the Wrocław Opera House the orchestra pit has been enlarged by moving its back wall further into the space beneath the stage. As a result, the orchestra pit is covered for about 40% of its length. The ceiling in the covered part has been lined with sound absorbing material. Also a floor with adjustable elevation has been installed in the pit's open part. Measurements of sound strength (G) for a source located under the overhang were performed on the ground floor, on the balconies, on the stage and at the conductor's stand. The measurements were carried out for: two pit floor levels, two sound source elevations and reflective versus absorptive ceiling above the source. The measurements showed that as a result of the replacement of the sound absorbing ceiling with the reflective one the strength of sound from the source under the overhang has increased. The difference in G exceeds the threshold value. An increase in G was perceptible on the ground floor and on the balconies when the pit's floor and the sound source were raised at the same time. Raising the floor alone without raising the source did not produce an increase in sound strength.

Changing the early reflections in vineyard concert halls

PACS: 43.55.Ka

Chiang, Wei-hwa; Chen, Yi-run

Department of Architecture, National Taiwan University of Science and Technology, #43,Sec.4,Keelung Rd.,Taipei,106,Taiwan; D9413002_at_or_arroba_mail.ntust.edu.tw

In concert halls the walls are always thought to be the most important elements for effective early reflections, while usually in a vineyard hall people may find the area of roof ceiling is comparatively larger than walls. Thus their contents of early reflections are different, both in time and energy domain. Using computer model with ODEON, the prototype of vineyard hall developed in pilot projects was compared with four selected successful shoebox halls in similar volume or seating capacity, the acoustic performance including the strength and balance are considered. The study is focus on the amount and direction of early reflections after direct sound arrived, displayed in three different time window. The effects of altering the distribution curve of statistical free path length by changing geometric characters of prototype were also observed.

A basic study on the difference of preference on acoustic condition between conductor and players in orchestra

PACS: 43.55.Fw

Tokunaga, Yasunobu¹ ; Terashima, Takane²

¹Graduate school of Mie Univ.; 1577, Kurimamachiya-cho, Tsu, Japan; tokunaga_at_or_arroba_e.arch.mie-u.ac.jp
²Graduate school of Mie Univ.; 1577, Kurimamachiya-cho, Tsu, Japan; tera_at_or_arroba_arch.mie-u.ac.jp

For stage acoustic design in auditorium, it is necessary to offer acoustic considerations not only for instrument players but also for conductor. In case of orchestra music, a conductor has an important role to control whole players of orchestra and then the stage acoustic condition should be designed for conductor rather than players. But acoustic condition for orchestra conductor has not been studied well ever and also the relation of good acoustic condition for conductor and players has not been cleared ever. It is necessary to prove the difference of subjective responses between them to establish the method of stage acoustic design. The purpose of this paper is to find the differences of preference properties for identical acoustic condition between conductor and instrument players. In the experiments, 3 subjects (a conductor and 2 players) who compose a minimum orchestra model were asked to play music in several simulated sound fields, which were virtualized by real time convolution and were presented through headphones. After played music, subjects were asked to answer the subjective preference and as a result, the difference of subjective evaluation between conductor and players were shown.

Acoustical treatment of the Carolina Coronado theatre in Almendralejo. The employment in theatre of a dynamic acoustic shell with diffusers.

PACS: 43.55.Fw

Martín Castizo, Manuel¹; Maderuelo Sanz, Rubén¹; Bejarano Durán, Fernando¹; Durán Ara, Javier²

¹INTROMAC; Campus Universitario s/n, 10071 Cáceres, Spain; mmartin_at_or_arroba_intromac.com
²Andor Acústica S.L., Zarzuela, 8, 45003 Toledo, Spain

The Carolina Coronado Theatre from Almendralejo inaugurated in 1916, was one of the pioneers in Extremadura (Spain). The rehabilitation was done in 2004 by the Government of Extremadura to recuperate the theatre original splendour. In 1971 was converted by his previous owner in a cinema, when some signs of identity were eliminated as theatre. The original design follows the traditional horseshoe arrangement used everywhere during 19th century. In the Carolina Coronado Theatre the V/N ratio (7.049/650) is 10.84 and the reverberation time (RTmid), with audience, is 3.33 sec. These are far away of the recommended values. The treatment was done without changes in the walls respecting faithfully the original appearance of the room, also above the stage was used a new concept of acoustic shell based in diffusers that, with its dynamic, can be used for theatre plays by the creation of different “acoustical ambience”. In this paper are described the most relevant aspects of the acoustical treatment, the results were obtained of the simulations and measurements in situ.

PACS: 43.55.Gx

Defrance, Guillaume¹ ; Polack, Jean-Dominique¹ ; Katz, Brian FG²

¹Institut Jean le Rond d'Alembert –Lutheries, Acoustique, Musique (LAM); Université Pierre et Marie Curie / CNRS UMR 7190 / Ministère de la Culture et de la Commnication, 11 rue de Lourmel –75015 Paris, France; defrance_at_or_arroba_lam.jussieu.fr; polack_at_or_arroba_ccr.jussieu.fr.
²Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur (LIMSI) – CNRS, B.P 133 91403 Orsay Cedex France; brian.katz_at_or_arroba_limsi.fr.

Room acoustics measurements have been conducted in the newly renovated Salle Pleyel, in Paris, in order to characterize changes in the acoustics of the hall since its reopening in September 2006. These measurements were made with a simple setup, and data were treated with two different analysis packages: the Room Acoustics Toolbox (RAT) and a renovated version of MIDAS, created in the late 1980's, by Polack, Marshall and Dodd [1]. Both packages run under MatLab The aim of this paper is on the one hand, to update the public database of acoustic indices of the Salle Pleyel, comparing them with those found in the past by previous studies and, on the other hand, to compare results provided by the two codes. The differences will be presented as well as different parameters settings. The paper concludes with a short presentation of the features of the new MIDAS package, destined to be made available to the public.

PACS: 43.20.Dk; 43.20.El; 43.55.Ka

Sumbatyan, Mezhlum A.; Boyev, Nikolay V.

Faculty of Mathematics, Mechanics and Computer Science; Southern (Rostov) Federal University. Milchakova Street, 8a, 344090 Rostov-on-Don, Russia; sumbat_at_or_arroba_math.rsu.ru, boyev_at_or_arroba_math.rsu.ru.

Very often the spaces considered in the ambit of room acoustics possess non-pane reflecting surfaces (Baroque-style constructions, Orthodox churches, etc). The nowadays approaches to simulate such reflecting surfaces operate with them like with a set of plane patches globally forming the real crooked surface. This technique implies that the wave interaction with the crooked surface is locally the same as in the case of purely plane surface that is not correct. In the present work we give correct formulas for acoustic ray interaction with arbitrary smooth non-plane reflecting surfaces and demonstrate the application of these theoretical results by some test examples.

Reconstruction of the opera hall in Maribor – case study

PACS: 43.55.Fw

Mijić, Miomir; Šumarac Pavlović, Dragana

Faculty of Electrical Engineering, Belgrade, Serbia; emijic_at_or_arroba_etf.bg.ac.yu

The consulting team of Acoustics Laboratory at the Faculty of Electrical Engineering in Belgrade was invited to redesign the Opera hall in Maribor, Slovenia. The project was done in cooperation with Janez Lajovic, an architect from Ljubljana. The basic geometry of the Opera hall has some unfavourable proportions and the improvement in the acoustical characteristics was a great challenge. In addition, this job was interesting as the hall was available for measurements before, during and after the renovation. The measurements enabled gathering of useful information about the acoustic response in similar halls.

How to improve speech intelligibility in class- and lecture rooms

PACS: 43.55.Hy

Čudina, Mirko¹; Prezelj, Jurij²

¹University of Ljubljana; Faculty of Mechanical Engineering, Aškerčeva 6, 1000 Ljubljana, Slovenia; ¹mirko.cudina_at_or_arroba_fs.uni-lj.si; ²jurij.prezelj_at_or_arroba_fs.uni-lj.si.

Room acoustic is different for classrooms or lecture rooms and for concert or opera halls and churches. The most important parameter for class- and lecture rooms is speech intelligibility. Speech intelligibility depends on the reverberation time, speech to noise ratio, dimensions of the classroom, visibility of the speaker, position of the listeners etc. To improve speech intelligibility in an existing class- or lecture room we have to increase the signal to noise ratio or to reduce the reverberation time. For reducing reverberation time, different engineering methods are in use. Instead of the engineering methods an alternative method can be used, e.g., by hanging art paintings on the room walls. Experiments have shown that paintings can reduce reverberation time by increasing of the absorption coefficient in the most audible part of frequency spectra, between 800 and 1500 Hz. This effect can be increased by adding an absorption material behind the canvas of paintings. Art paintings can also be used for educational purposes and by proper colour combination for soothing of the undesirable background noise by changing perception in the brain.

Changes in reverberation affect speech intelligibility within the classroom

PACS: 43.77.Gv

Oiticica, Maria Lúcia G. da R.¹; Bertoli, Stelamaris Rolla²

¹PhD Student of the School of Civil Engineering and Architecture and Urban Design – Department of Architecture and Building. State University of Campinas–UNICAMP – Campinas – SP, Brazil; mloiticica_at_or_arroba_hotmail.com
²Prof. Dr. School of Civil Engineering and Architecture and Urban Design – Department of Architecture and Building. State University of Campinas–UNICAMP – Campinas – SP, Brazil; rolla_at_or_arroba_fec.unicamp.br

Due to growing concern over the suitability of educational facilities, the importance of acoustics within schools has been widely discussed over the past few years. A number of papers have shown that reverberation and excessive noise degrade speech intelligibility, thus hindering the learning process. This paper was aimed at investigating speech intelligibility within a classroom by changing seating arrangement and reverberation time. The research was conducted at the State University of Campinas - São Paulo, Brazil, in a standard classroom occupied with 50% of students ontologically normal. Students were given speech intelligibility tests that used lists of language phrases found in audiological tests in Brazil. The speakers were both male and female. A more absorptive material was employed in one of the surfaces of the wall so as to change reverberation time. Seating arrangement was modified relative to the distribution of the acoustical material. The sound equipment was placed where the teacher would be and an approximate 65 dB(A) sound level was measured at the farthest point from the source. In order to assess the acoustical condition within the classroom, reverberation time (RT) and background noise levels were measured in many a situation (including with the students present).

Concepts of room acoustics in environmental noise maps

PACS: 43.50.Rq

Schreurs, Eric¹; Jabben, Jan²

RIVM National Institute of Public Health and Environment, Postbus 1, 3720 BA, Bilthoven, The Netherlands; ¹eric.schreurs_at_or_arroba_rivm.nl; ²jan.jabben_at_or_arroba_rivm.nl

Current noise impact assessments are largely based on broadband A-weighted Noise indicators. These indicators only partly explain annoyance and sleep disturbance due to noise. A more complete picture and better correlation with annoyance and health effects may result from indicators that also include temporal aspects and frequency character. This paper gives preliminary results of a project at RIVM that aims at developing noise maps in which background levels, maximum noise levels and low frequency character are taken into account. The first stage deals with modelling these indicators for environmental noise in urban areas. In these areas, reflection and diffraction effects from buildings pose difficulties in determining accurate noise maps. The paper discusses methods for dealing with these problems using concepts of room acoustics. Furthermore a statistical technique for modelling background levels and preliminary results are presented.

Utilization of waste materials for sound absorption

PACS: 43.55.Cs

Vašina, Martin

Tomas Bata University in Zlín, Institute of Physics and Material Engineering, Nad Stráněmi 4511, 760 05 Zlín, Czech Republic; vasina_at_or_arroba_ft.utb.cz

Noise belongs to negative effects in our environment. One of possibilities of noise elimination is application of suitable materials with good sound-absorbing properties. Porous materials belong in general to materials capable for noise damping. The purpose of this paper is to investigate sound-absorbing properties of selected waste materials with different thicknesses. Experimental measurement of sound absorption coefficient was carried out on Brüel & Kjær 2034 analyzer with Kundt's tube in the frequency range of 16 to 6300 Hz.

The acoustic design of the main hall of the “Alma Mater Studiorum“

PACS: 43.55.Cs

Tronchin, Lamberto; Tarabusi, Valerio

DIENCA – CIARM, University of Bologna; Viale Risorgimento 2, 40136 Bologna, Italy; tronchin_at_or_arroba_ciarm.ing.unibo.it; www.ciarm.ing.unibo.it

The University of Bologna, which started in 1088, opened in 1988 the new Main Hall, after restoration of a former Jesuits church, which was founded in 1623 and partially modified in 1843, on the site where S. Petronius founded a church devoted to S. Lucy, in 432. The new Main Hall showed strong acoustic defects since his opening. The church has one high nave, plastered walls and a reflecting pavement. The lateral chapels of the church, as well as the huge volume (about 30000 m³) provoked a very high reverberation in the church, which is not mitigated by the not upholstered seats in the hall. The acoustics was partially enhanced by means of an electroacoustic system, which was able to partially redirect the sound directly to the audience. However, acoustic design of the hall was required to improve the sound distribution, even though already repeatedly proposed in the past. In this paper a new acoustic design of the hall is presented. Starting from recent acoustic measurements, the proposed enhancements cover many components in the church, but still maintaining its peculiar architectural aspect: acoustic plaster, curtains, and a set of transparent, flexible acoustical panels, which could move and turn separately, redirecting sound propagation in the hall. Finally, the acoustic enhancements are presented by means of 3D Auralization.

From Prometheus's Arc to Akiyoshidai. Principles of stage design for the "multifocal" repertoire of the second half of the XX century

PACS: 43.55.Fw, 43.55.Gx

Moreno Soriano, Susana¹; Carretero Llorente, Clara²; Carballal Luengo, Pablo²; Martínez Sanz, Ignacio².

¹Departamento de Tecnología de la Edificación. Escuela Superior de Arte y Arquitectura de Madrid. Universidad Europea de Madrid. susana.moreno_at_or_arroba_uem.es.
²Departamento de Construcción y Tecnología Arquitectónicas. Escuela Técnica Superior de Arquitectura de Madrid. Universidad Politécnica de Madrid.

We are presenting an analysis of the successive staging (1084-1998) of "Prometeo, tragedia dell'ascolto" by Luigi Nono in different theatres of the world , as a paradigm example of the search for an acoustic space appropriate for multifocal music in the second half of the 20th century. The play was first staged in Venice, in Saint Lawrence's Church and inside it Prometheus's Arc was built, following instructions from the composer. After 1985 it was brought to different spaces where various adjustments were needed for the play to be performed, firstly under the composer's supervision, until he died, and then under André Richard. In 1998, with the musical advice of André Richard's and Nagata Acoustics, a special Hall was build in Akiyoshidai (Japan) to show Prometheus permanently. From this example, information about different aspects and conditions in the design of Theatres suitable for this particular repertoire can be classified and analysed. A typological review is proposed covering: space conditions, functional conditions and the criteria to optimise acoustic parameters.

Evaluation of acoustic properties of floating floors and materials used under floating floors for approval and certification aims. Classification of stiffness and impact sound reduction applied in Poland

PACS: 43.55.Cs

Mirowska, Marianna ¹, Tomczyk, Paweł ²

ITB Building Research Institute, Acoustics Department, Warszawa, Poland ¹M.Mirowska_at_or_arroba_itb.pl; ²P.Tomczyk_at_or_arroba_itb.pl

In the paper, problems of evaluation of acoustic properties of floating floor products for purpose of approval and certification are discussed. The principles of determining the declared (required) values of dynamic stiffness s' of building materials and impact sound reduction level ΔL_w of floor coverings are presented. Stiffness and impact sound reduction classes used in Poland for assessment of floating floor products are given.

A general acoustic characterization of the Maestranza theatre in Seville

PACS: 43.55.Gx

P. Bustamante¹, T. Zamarreño², S. Girón², M. Galindo², J. J. Sendra¹.

¹Dept. Construcciones Arquitectónicas I, Univ. de Sevilla, E.T.S. Arquitectura (IUCC); Avda. R. Mercedes 2, 41012-Sevilla, Spain;
²Dept. Física Aplicada II, Univ. de Sevilla, E.T.S. Arquitectura (IUCC); Avda. R. Mercedes 2, 41012-Sevilla, Spain;
bustamante_at_or_arroba_us.es, teofilo_at_or_arroba_us.es, sgiron_at_or_arroba_us.es, mgalindo_at_or_arroba_us.es, jsendra_at_or_arroba_us.es.

This paper constitutes the preliminary results of an acoustic analysis carried out in the Maestranza Theatre, the most emblematic concert hall in the city of Seville (southern Spain), as part of a more general aim to establish the room acoustic parameters that determine the acoustic quality of concert halls. The spatially averaged values of time parameters, energy parameters, sound pressure levels and lateral energy as a function of frequency are presented and discussed for three different zones in the audience area and some special behaviour observed in the central audience area is emphasized. This work has been undertaken in the framework of a coordinated research project between several research groups of certain Spanish universities.