Salvador Cerdá

A Comparison of Different Techniques for Simulating and Measuring Acoustic Parameters in a Place of Worship: Sant Jaume Basílica in Valencia, Spain

The translation of this paper was funded by the Universidad Politecnica de Valencia, Spain.

A Factor Analysis Approach to Determining a Small Number of Parameters for Characterising Halls

The translation of this paper was funded by the Universidad Politecnica de Valencia, Spain.

Subjective ranking of concert halls substantiated through orthogonal objective parameters

This paper studies the global subjective assessment, obtained from mean values of the results of surveys addressed to members of the audience of live concerts in Spanish auditoriums, through the mean values of the three orthogonal objective parameters (Tmid, IACCE3, and LEV), expressed in just noticeable differences (JNDs), regarding the best-valued hall. Results show that a linear combination of the relative variations of orthogonal parameters can largely explain the overall perceived quality of the sample. However, the mean values of certain orthogonal parameters are not representative, which shows that an alternative approach to the problem is necessary. Various possibilities are proposed.

Historical and chronological evolution of the concert hall acoustics parameters

The present paper examines the historical evolution of the concert halls acoustic parameters, in the international field. From the beginnings of twentieth century, the acoustic parameters have had a continuous evolution, covering more and more aspects of the concert hall acoustics qualification. Since the bibliography about these is fragmented, we performed in this article, a global and updated presentation on the chronology and the evolution of the studied parameters. Considering the great variety of the same, we presents the appearance of each parameter, located in decades, who has proposed them and, where is possible, indicates articles or publications where they have been presented for the first time. Thus, the historical presentation of the majority of the acoustic parameters of concert halls, it optimizes and can be useful for future research as a central platform in a bibliographical study. The presentation of the same is also grouped according to quality criteria.

Virtual Acoustic Reconstruction of the Church at the Lost Monastery of Santa Maria de la Murta

Archeological acoustics is a part of acoustics that studies ancient environments which were dedicated (completely or partly) to sound performing. The combination of this acoustic area in conjunction with room acoustics enables the study of the acoustic evolution of existing buildings (in terms of the historical documentation) or even, make the acoustic reconstruction of rooms which were destroyed or they are in a bad state or in ruins. In this work, an acoustical reconstruction of the church of the Hieronymites’ monastery of the Murta from the XIV century, in Alzira, Spain has been developed. This building was abandoned in 1836 and now is in ruins. The work develops a geometrical model, together with a proposal of materials which were common in the churches of the same area, an acoustical study and finally an auralization of a choral performance has been done (as this monastery had its own musical chappele).

Use of multiresolution analysis to calculate pitch in presence of noise.

The aim of this work was to determine the effect of noise presence at time to evaluate the pitch, and the study of possible improvements. Several algorithms (Terhardt, Duifhuis, Cepstrum, simple FFT, and visual determination) were studied. These algorithms were applied to different Spanish vowels with a progressively increased noise level; conclusions about the precision of each method are presented. In general, the noise causes a loss of accuracy because time‐domain data are blurred and spurious components appear in the spectrum. At this point the multiresolution analysis (MRA) technique becomes a useful tool to eliminate the effect of elevated noise level. MRA was used to smooth the vowels analyzed and then the algorithms under study were applied another time. With this procedure an accuracy improvement in all methods that work in the frequency domain was observed.

On the Relations Between Audio Features and Room Acoustic Parameters of Auralizations

The usual parameters in room acoustics are used to quantify the acoustic characteristics of rooms and their relation to the subjective perception of transmitted signals. Audio features (calculated with MIRToolbox) have been designed to study the relationships between the characteristics of musical audio files and their subjective perception. Both musical characteristics and acoustic parameters are oriented towards acoustic perception. By using auralizations with calibrated models of auditoriums and tools from the MIRtoolbox it is possible to jointly work with the calculation of audio features and room parameters. In this work, the statistical correlations between C80, STI, D50, EDT, RT and certain audio features have been analyzed. The Pearson r values are higher than 0.8 in all cases. These high correlations enable acoustic parameters to be calculated from the musical characteristics of auralized audio signals.

Objective Evaluation of the Width of Source Ensemble in Virtual Halls

In this work, we study the effects of the width of the sound source in several acoustical virtual room models with different topologies, sizes and uses, calibrated with commercial software. To achieve this aim, a square distribution of sound sources with variable side length has been considered. We have auralized four channels of speech signal and musical signal in three different locations in each room. By using signal processing techniques, a comparison of multisource auralizations with the ones obtained from a single source in the middle of the stage is made. Also, the variations between the usual room parameters obtained from these simulations are analyzed, in order to show the effect of the hall in the objective evaluation according to the source width.Paper NCAD2012-72001 is available online only.Copyright

Establishment a methodology for an objective‐subjective acoustic analysis in a multifunctional hall: Paraninfo of the Polytechnic University of Valencia

This study presents a methodology for the acoustic analysis, from a comprehensive study of a multifunctional hall, of the Polytechnic University of Valencia, as a pilot hall in a Spanish Coordinated Project. The acoustic parameters studied were those who the most acoustics experts consider of interest. In the objective measures were use the equipment and methods conforming to ISO 3382. The questionnaire used to analyze the subjective response has been patented in Spain, by the research group that developed the project. The correlation between objective and subjective results, along with the accurate simulation of the hall provides a valid tool for design, restoration and improvements the enclosures where the sound quality is preferred.

Noise exposition in the daily life

Nowadays, the man lives exposed in a world of sounds (pleasant ‐ disagreeable, nonannoying ‐ annoying) throughout the time, during the 24 hours a day. The man is exposed to the noise in his daily life, since he awakes, moves, works, entertains itself, rests, and to sleep. We have made a survey of levels of exhibition to the noise, having distinguished they are leisure, work or rest, in a amog young population of 20‐35 years without hearing problems, and of both sexes. The results show us and agree with other authors, that the exhibition levels are highest in the activities chosen, like for example the leisure. In addition, the levels of exhibition, to the noise are related with the diverses activities of the population.