Hall Design Research Articles

A neural network analysis of the effect of geometric variables on concert hall G values

This paper deals with the schematic design of large rooms (concert halls) using artificial neural networks. Previously published research has shown that neural networks can be used to predict the acoustical attributes ( G, C 80, LF and RT 60) of concert halls. Neural network analyses have been undertaken, and the changes in neural network predictions of the parameter strength factor, G, according to the variations of concert hall design variables, has been investigated. The results of the analyses are difficult to describe simply as there appears to be a non-linear relationship between some of the many input variables. Seven concert halls have been used to show how the change in certain geometric variables will influence G values.

Padre Pio Church, Foggia, Italy

This article discusses the construction solutions and structural design of the Liturgical Hall dedicated to Padre Pio in the San Giovanni Rotondo. The concept of constructing with a traditional material such as stone, and using it in a modern and innovative way inspired the engineering design team’s interest in this project. Using proper calculation codes, static as well as dynamic analyses were carried out. These analyses were able to provide sufficient indication of the real behaviour of the structure. The entire project was backed by a complete series of experimental trials dealing with the singular materials and the construction systems.

Early reflection energy in concert halls: how much, how early, and from where

Today, the importance of distributing early reflection energy to listeners and performers in concert halls is well understood and accepted—also among architects. Still, implementation in the practical design of a large hall is not easy, partly because we still have difficulties quantifying precisely the demands in detail (how much, how early, and from where) due to limitations in our acoustic knowledge—and often also due to little response from the clients regarding their preferences when decisions between alternative demands must be made. Therefore, in general it is up to the acoustician to decide how far to promote the good cause on the basis of his/her experience, taste, and talent in influencing the decision process. The aural presentation will focus on the current limitations in our knowledge regarding the musicians’ need for early reflections, which is a special challenge in the design of terraced, ‘‘surround’’ concert halls. In the case of the listeners, knowledge has reached a much higher level, and recent results regarding how room shape influence the objective acoustic parameters monitoring the early energy will be presented.

Applications of physical and mathematical modeling in concert hall design

A variety of testing methods were employed throughout the early and mid stages of design for an eighteen-hundred-seat flexible-use concert hall. Full-scale laboratory testing, model-scale measurements, and mathematical modeling were undertaken to provide guidance on particular design decisions. Mathematical techniques were used to guide the full-scale laboratory testing, and full-scale testing results were applied in the model-scale measurements. Auralization techniques were implemented to study specific effects.

Priority‐Driven Acoustic Modeling for Virtual Environments

Geometric acoustic modeling systems spatialize sounds according to reverberation paths from a sound source to a receiver to give an auditory impression of a virtual 3D environment. These systems are useful for concert hall design, teleconferencing, training and simulation, and interactive virtual environments. In many cases, such as in an interactive walkthrough program, the reverberation paths must be updated within strict timing constraints ‐ e.g., as the sound receiver moves under interactive control by a user. In this paper, we describe a geometric acoustic modeling algorithm that uses a priority queue to trace polyhedral beams representing reverberation paths in best‐first order up to some termination criteria (e.g., expired time‐slice). The advantage of this algorithm is that it is more likely to find the highest priority reverberation paths within a fixed time‐slice, avoiding many geometric computations for lower‐priority beams. Yet, there is overhead in computing priorities and managing the priority queue. The focus of this paper is to study the trade‐offs of the priority‐driven beam tracing algorithm with different priority functions. During experiments computing reverberation paths between a source and a receiver in a 3D building environment, we find that priority functions incorporating more accurate estimates of source‐to‐receiver path length are more likely to find early reverberation paths useful for spatialization, especially in situations where the source and receiver cannot reach each other through trivial reverberation paths. However, when receivers are added to the environment such that it becomes more densely and evenly populated, this advantage diminishes.

Acoustical Design and Measurement of a Circular Hall for Improved Spatial Factors at Each Seat

A round-shaped multi-purpose event hall (ORBIS Hall, Kobe, Japan) was designed based on the subjective-preference theory of sound fields [Y. Ando, Architectural Acoustics -Blending Sound Sources, Sound Fields, and Listeners-, AIP Press/Springer-Verlag, New York, 1998]. To avoid acoustical problems produced by round-shaped walls, and to maximize the total scale value of the subjective preference at each seat, acoustical features including several kinds of reflectors were carefully designed. The IACC calculated for the design phase, however, did not include all the installed features because these have complicated scattered reflection characteristics. After construction of the hall, therefore, the IACC measurements were conducted using two different music motifs. Results indicate that the values of the IACC are much improved due to these features. Also, the SPL-dip in the low frequency range in the area close to the stage is effectively improved by the inclusion of a perforated floor.

Visual assessments of the surface diffusion properties of concert halls

The diffusion of sound in concert halls has been recognized as significant in determining the acoustic quality of halls. The diffusion of sound in rooms is difficult to assess as are the diffusing properties of surfaces. The collective diffusing properties of the walls, floor and ceiling in a hall would seem to be almost impossible to assess objectively but such an assessment is needed for the design of concert halls. In this paper it is shown, indirectly, that visual assessments of the diffusion of concert hall interiors appears to be repeatable and reproducible to a degree which will allow halls to be designed to one of three broad classifications; “excellent”, “good” or “fair”.

Pounding Response of Adjacent Buildings Subjected to Spatial Earthquake Ground Excitations

Pounding damage is a serious seismic hazard in highly populated areas during major earthquakes. This paper evaluates the effect of earthquake ground motion spatial variations on pounding responses of adjacent structures. Adjacent structures are modeled as two single-degree-of-freedom (SDOF) oscillators with multiple supports. Pounding effects are simulated by spring-dashpot pounding elements. Linear elastic and nonlinear inelastic responses are considered in the analysis. Spatial ground motion input is stochastically simulated. The simulated spatial ground motion time histories are compatible with Newmark and Hall design spectrum individually and with an empirical coherency function between each other. The Newmark method with constant acceleration assumption is employed in step-by-step integration to calculate structural response. Numerical results are presented and discussed in terms of various structural and ground motion parameters.

The Vern Knudsen Lecture: The compleat concert hall: A century of acoustics development and its lessons for the design of concert halls

From the opening of Carnegie Hall just before the turn of the (20th) century, the art and science of concert hall design has advanced significantly...but that advance has been over many bumpy roads and with a number of detours along the way. As a profession we need to do all we can to assure that the halls we build in the future will serve as well in a hundred years as those that were built a century ago. In some instances that is a very tall challenge indeed. This provocative paper seeks to be visionary as well as retrospective, laudatory as well as critical. It is illustrated by experience and observation and delivered with respectfulness, but with enough challenge and irreverence to stimulate thoughtful and challenging discussion.

Recent multi-purpose hall designs in Denmark with physically variable acoustics

This paper describes two recent Danish multi-purpose hall designs, in which acoustic variability has been accomplished in different ways: through variable absorption and variable volume, respectively. The different approaches were chosen in order to insure that not only reverberation time (T) and so clarity (C), but also the strength parameter (G) could be varied in a favorable direction in view of the prescribed uses of the halls. The hall with variable absorption is the assembly hall in the new extension to the Royal Library in Copenhagen to open in fall 1999. This hall will seat 600 people and be used for chamber music concerts, symphony orchestra rehearsals, and amplified speech. For the latter two functions, a reduction in G along with reduction in T was considered favorable. The hall with variable volume is the recently opened Esbjerg Musikhus seating 1100 and equipped with a full stage house. This hall is used for symphonic concerts and musicals as well as drama and conferences. In this hall, maintaining or even increasing G along with a reduction in T is advantageous, especially in the drama theatre mode. The paper will describe the design of these two halls along with acoustic measurement results.

Links between concert hall geometry, objective parameters, and sound quality

For decades, the design of concert halls was driven by considerations of time history alone (T60, C80, ITDG), and as a result, little importance was attached to room geometry. The subjective importance of binaural dissimilarity has been a strong, though often simplistic, influence on recent designs. While listening experience has shown which fundamental room forms sound better than others, computer modeling and statistical analysis have enabled systematic investigation of the degree to which the geometry affects the sound. Using simple parametric models, this study will investigate effects of surface parallelism, concavity, and convexity on spatial and monaural objective acoustical parameters and on essential subjective attributes.

Room acoustic simulation in the planning of concert halls and opera houses

In room acoustic planning and design of concert halls and opera houses, computerized prediction of sound transmission gains an increasing significance. The room acoustic simulation may give a more reliable prediction of the room acoustic conditions to be expected. Furthermore, the visualized and auralized results have a positive effect on the communication between acoustician and architect. In this paper, the requirements as well as present possibilities and limitations of room acoustic prediction in practice are described by means of exemplary current building projects. Some important aspects such as coupled volumes, diffuse wall reflections, curved surfaces, or grazing sound transmission above the audience are discussed.

Acoustical design of the Marienkirche concert hall, Neubrandenburg

St. Mary’s medieval gothic cathedral in Neubrandenburg, Germany, was ruined at the end of World War II. Two decades ago a decision was made to turn it into a concert hall. The design started in 1996 with the architectural competition, won by Architects Pekka Salminen. The hall will be a combination of old brick walls and mullioned windows, joined with modern glass and concrete. The back wall and the ceiling are made of glass. An audience of 1200 maximum is divided into three blocks: stalls, a balcony, and a tier behind the stage. The initial properties were promising: rectangular, 21 m wide, 18 m high, and with inherent diffusion. The acoustical design was challenged by the restriction of not to touch the old restored side walls. A full-audience reverberation time of 2.0 s was set as a goal. Other objectives were moderate reverberation rise in bass, strong spaciousness and lateral energy. The acoustics were designed with a computer using the Odeon hall design program. Main new elements of acoustical control are a cloud array above the stage, triangular sails near the side wall cornices, and glass reflectors beside the stage. The hall is expected to be inaugurated in autumn 1999.

Scale model experiences in concert and opera hall design

Scale model experiments were executed for two concert halls and two opera houses which recently opened in Tokyo. Based on the geometrical acoustic analysis by using CAD model, effective room shapes were studied so as to minimize the extra labor at the scale model test. Then, 1:10 scale models made of wood and proper acoustical materials were constructed. Up-to-date digital signal processing technique was applied in order to improve the accuracy of the experiment. Also, several new ideas concerning the sound source, receivers, scale modeled seatings, and how to calibrate the air absorption were introduced, intended for the precise prediction of the room acoustical parameters. Thus, monaural parameters RT, EDT, C80, D, G, and ST, and binaural parameter IACC were measured in the scale models, and they were compared with those measured in real halls. The accuracy and problems of this method were discussed with the acoustical data found here.

Consistency in acoustic design when building symphonic performance halls

The acoustic success of all concert hall designs depends on meeting the subjective response of the audience and the performers. Since it is now possible to correlate subjective preferences of listeners and players with quantitative physical acoustic criteria, it is axiomatic that the acoustician should be consistent in setting acoustic environmental criteria for all spaces programmed for symphony performances. This paper describes the application of key physical acoustic criteria related to hall liveness, warmth, and intimacy in the design of rectangular and surround concert halls, multiuse proscenium style performances spaces, and symphonic music pavilions. In addition, the authors will illustrate how the consistent application of these same acoustic criteria can enable the practitioner to develop successful symphony halls and virtual concert facilities utilizing electronic reflected energy systems (ERES). All of the facilities described in this paper incorporated the reflections corelated to listener and performer preferences and were extremely well received by audiences, performers, and the press.

For A Better Acoustical Environment. 4. Recent Development of Acoustical Design of a Concert Hall.

For A Better Acoustical Environment. 4. Recent Development of Acoustical Design of a Concert Hall.

Design criteria for organ performance halls and concern halls with organs

While it is generally understood that reverberation time is an important criterion in designing an organ performance hall, little has been written on the importance of the organ’s transient response or its unique distribution in space. Whereas an orchestra is generally confined to a stage platform, the organ pipe chests may rise to different levels at heights 15–40 ft or more above the stage. As a result, EDT, C50, C80, IACC and other parameters sensitive to placement of the source may vary significantly between the stage platform and various divisions in the organ. This spatial differentiation is an important element in the design of an organ performance hall. Integration of an organ in the design of either a concert hall or recital hall presents several design challenges. The physical height of the organ is often in conflict with the need to provide early reflections for ensemble support. Optimal criteria for RT, G, C50, C80, and other acoustical parameters may also be at odds, paticularly in a University recital hall. The spatial distribution of the organ may play an important role in meeting these design challenges.

Concert hall research: Balancing complexity and practicality

An approach that has carefully balanced complexity and practicality has led to several new developments in concert hall research. These new developments are reviewed and their practical implications are explored. The two separate dimensions of spatial impression, apparent source width and listener envelopment, are each related to different physical parameters. The relationship between these acoustical parameters and the design of halls will be explored. For example, listener envelopment is related to the relatively late arriving lateral sound energy. Measurements in a number of halls will be used to explore how this and other acoustical measures of spatial impression are related to hall design. This same new understanding of spatial impression can also further enhance our understanding of sound fields under balconies and help us to design improved electroacoustic enhancement systems. Spatial impression is also influenced by sound level and especially by lower frequency levels. The importance of levels and the balance between high- and low-frequency levels has often been neglected. New work relating the perception of bass and treble sound to different factors will be reviewed. Previous studies and new analyses will be used to explore how hall design can influence perceptions of tonal balance in concert halls.

Calculation and measurement of acoustic factors for the Kirishima International Concert Hall

The Kirishima International Concert Hall was designed by architect F. Maki with Ando’s acoustic design theory. It opened on July 22, 1994. The 770 seat main hall which has a volume of 8475 m3 was primarily designed for chamber music. Computer simulations made it clear that the acoustical design of the main hall would be an optimum solution with a plan like a leaf shape and a cross section like a bottom of a ship. These were solutions which satisfied requirements for both acoustical and architectural design concepts of the main hall. Getting a low IACC sound field at the front seat was most important. In order to get a low IACC, sound reflections from the stage to the audience floor were examined and studied in the early design processes. Calculation and measurement of acoustic factors of the sound fields in the main hall show: (1) the calculated and the measured IACCs are good in agreement, (2) IACCs tended lower values of about 0.1 than the calculated ones throughout the seats, and (3) the number of reflections needed for predicting IACC is recommended to be about 40 for the practical method of IACC calculation at the design stage of a hall.

Acoustic behavior of a tense-structure

During the design of a concert hall, the acoustical behavior of the sound field is often investigated by using numerical models. In the case of a restoration of the hall, or during the design of the orchestra chamber, acoustic measurements of impulse responses in the hall give precious information on the sound fields, e.g., RT, clarity, and so on. By using numerical simulation, it is then possible to verify the efficiency of the acoustic solution. Much commercial software is available, all of them following the geometric assumptions, as the Eikonal equation, while the diffraction and diffusion of sound are not usually taken into account, and all of them require the absorption coefficient of the walls. The tense-structure, on the other hand, is not so easy to model, owing to the peculiar characteristics, i.e., modal behavior and impossibility to measure the absorption of the membrane. In this paper, the design of an acoustic intervention in a tense-structure is shown. A procedure to find out the ‘‘equivalent absorption‘‘ of the membrane is shown. The results of such a model are compared with the experimental measures.