Architectural Acoustics Research Articles

The Georgia Tech West Village Building Multipurpose Space: A case study of a higher education multipurpose space with conflicting programming to find a practical and cost-effective solution for end users

This case study examines the challenges in architectural acoustics pertaining to small multipurpose rooms used for musical and instructional purposes as exhibited in the West Village Building on the Georgia Institute of Technology Atlanta Campus. The multipurpose space, while designed with variable acoustical elements, was challenging for the various user groups. This study aimed to find a solution to balance the acoustic, budgetary, and practical needs of this space. The goal of this study was to determine what configurations of existing and new material would improve functionality of the space. Solutions were created based on measured reverberation time of the space, and calculations based on properties of known materials and potential configurations. The findings were used to create a user-friendly guide for those who utilize the space, as well as an auditory demonstration. Most significantly, this study arrived at a solution that employed both existing and readily available materials, a modest budget, and maintained flexibility within the space.

Is that all the space you've got?

A few case studies regarding small room architectural acoustics concerns are presented. These address problematic and unanticipated low-frequency room modes, constraints regarding vertical sound isolation in a tenant-space theater, and challenges pertaining to control of a chiller plant in commercial office space. Our approach to criteria, analyses, noise control recommendations, and lessons learned will be presented.

Overview of technical certificate program from the Institute of Noise Control Engineering

Standards are often misunderstood by even the most seasoned of acoustic professionals, let alone new technicians and engineers in the field, as they are often very complicated, written in piecemeal fashion by committees and are updated often. Some of the standards even conflict with one another. To help alleviate this problem, the Institute of Noise Control Engineering (INCE) is developing two technical certificate programs designed to educate and evaluate participants on the details of common standards used in the noise control industry. Each program will contain education, testing, and continuing education on ASTM International and Acoustics Society of America (ASA) standards. The first program will cover general acoustical measurements and environmental noise measurements. The second program will cover field testing of building acoustics, including airborne and impact noise insulation as described in ASTM E336, ASTM E1007, and associated standards. The courses are currently being developed with a target launch date of early 2023. Comparisons to similar programs that have been developed in other countries will be included. A business case will be made on how these programs will save noise control engineering firms time and money in training new staff.

Review: Echo’s Chambers: Architecture and the Idea of Acoustic Space

Review: <i>Echo’s Chambers: Architecture and the Idea of Acoustic Space</i>

Modelling and visualization for the analysis and comprehension of the acoustic performance of buildings through the implementation of a building information modelling-based methodology.

Technical and technological advances have revolutionised the architecture, engineering, and construction industries in recent decades. Building information modelling (BIM) methodology has become essential in the process of information management and the development of building projects. This study aims to analyse the potential advantages of the implementation of BIM-based models for the acquisition of theoretical and procedural knowledge about building acoustics. This procedure was implemented as part of a problem-solving exercise in Science, Technology, Engineering, and Mathematics (STEM) university degrees. For this purpose, three-dimensional (3D) BIM models were generated to assess the contribution of their implementation in the process of visualization, comprehension, and analysis of the acoustic behaviour of buildings. The participants' experiences and satisfaction with the BIM models were measured through a questionnaire. The results showed a high level of satisfaction among the participants and good potential for the application of 3D models based on BIM methodology for the acquisition of knowledge and practical skills in building acoustics. These results highlight the potential of BIM models to provide information for understanding the procedure followed during data collection in the experimental analysis and to facilitate the understanding of system behavior.

Temel Bina Akustiği Uzmanlık Eğitimi Önkoşullarının İç Mimarlık Bölümü Üzerinden Sorgulanması

Building acoustic is an integral part of building physics in the field of architecture and interior design all over the world and plays a major role in providing auditory comfort conditions. According to the regulation published in the official gazette in Turkey in 2017, it has become obligatory to submit acoustic projects and reports at the license stage for buildings over certain number of floors and total area. These reports and projects can be prepared by acoustic experts who have the D1 Basic Building Acoustics Specialization Certificate. While it is sufficient to have a bachelor's degree in architecture and engineering to satisfy the prerequisites of participation in the D1 basic building acoustics certificate training, interior architecture undergraduates are entitled to attend this training only if they have a master's degree in acoustics. In this context, to examine this restriction, the qualifications expected from the people who will participate in the certificate training were determined by a preliminary survey study conducted with the instructors who are authorized to give basic acoustic training. Then, the level of the fulfillment level of the interior architecture graduates on determined qualifications was revealed via a questionnaire survey conducted with the heads of the interior architecture departments in Turkey who have a good knowledge of the interior architecture department outputs.

Approximations: On Some Ways to Listen to a Building “in the Making”

What sounds and noises does a future building make? How do architectural acousticians listen to a building in the making? How do you measure something that is not yet there? What is the epistemological status of approximations? Following the listening practices of acousticians as they measure a future experience of sound through a mock-up and of noise through an incomplete simulation, this article explores the challenge of fixing sound and noise as elusive objects of knowledge. Based on an ethnography of a building project, we see how architectural acousticians rely on what they call “approximations,” both the inscriptions and inscriptive work used to give traces of reality to future lived experiences of sound and noise that they hope “would be” there. Bringing together sound studies, ethnographies of architectural practice and science and technology studies accounts of inscription practices, the article argues for attention to be placed on the ephemera of knowledge and design practices, which allows analytic focus to remain upstream between the possible and the actual. Situated within the practices of the acousticians, we can witness some of the ways that sound and noise take shape within a building project, grosso modo.

The acoustics program at the Institute of Acoustics, Tongji University, China.

The acoustics research at Tongji University began in the mid-1950s. The Institute of Acoustics (IOA) of Tongji University, which is one of the earliest institutions engaged in acoustics research in China, was formally established in 1984. The IOA has decades of experience in acoustics education, including offering a master's degree program for approximately 40 years, a Ph.D. program for 35 years, and a postgraduate program for 25 years. The IOA is one of the oldest acoustic research facilities in China with outstanding acoustics laboratories. Research at the IOA is performed in many areas of acoustics, which focus on detection acoustics and marine acoustics, laser ultrasonics and photoacoustics, medical ultrasonics and bioacoustics, architectural acoustics, environmental acoustics, noise control, functional and microstructural acoustic materials, aeroacoustics and aeronautical acoustics, and vehicle acoustics. This paper presents acoustics education at the undergraduate and graduate levels of Tongji University and its outstanding acoustics research facilities in detail.

Advancing support for cause-and-effect models by estimating the kurtosis statistic using fractional-octave-band filters

This paper presents a preliminary method for estimating signal processing parameters that optimally satisfies accuracy and resolution requirements for the sound pressure level and kurtosis level. The kurtosis statistic has long been studied and more recently used for applications in acoustics and vibrations such as architectural acoustics, hearing loss, noise exposure, and accelerated material and structural life testing. The temporal and spectral characteristics of many quantities are evident by time-frequency analysis including hearing, finger sensation, sound diffusion, and reverberation. Some research has conditioned on frequency content while other research has not. Simpson's reversal may potentially adversely affect the models if frequency content is not considered. Modeling techniques which relate cause-and-effect are more likely to result in successful models. Models of human hearing are particularly sensitive to the frequency content because the tonotopic organization of the cochlea induces a cause-and-effect relationship from sound incident on the ear to the basilar membrane. The fractional-octave-band filters specified in ANSI S1.11 and IEC 61260-1 are well developed for conditioning on frequency bands. This paper provides details of the process for optimizing the filter parameters. Additional optimization and testing is described for developing a faster and more accurate method with better support for causal inference.

High-Efficient and Broadband Acoustic Insulation in a Ventilated Channel With Acoustic Metamaterials

Acoustic insulation in ventilated structures is an important problem in acoustic engineering with many potential practical applications, such as the noise control for ventilating ducts of buildings, vehicles, or air conditioners. Acoustic metamaterial is a good candidate for the design of acoustic insulation for ventilated channel (AIVC) because the structural design with hard boundary has longer lifetime than conventional sound-absorbing cotton. In this paper, an AIVC with an open region and narrow channels of different lengths is proposed. We numerically and experimentally demonstrate its acoustic insulation larger than 20 dB (T &amp;lt; 0.01) within approximately 500–1,200 Hz with a subwavelength channel length of λ/6. The parameter dependence and air flow effect are numerically studied. Our findings show an alternative design of AIVC that may have applications in noise control and architectural acoustics.

Low-Frequency Dual-Band Sound Absorption by Ultrathin Planar Wall Embedded With Multiple-Cavity Resonators

We report the numerical and experimental realization of a type of ultrathin planar wall with low-frequency dual-band sound absorption. The proposed planar wall is constructed by a periodic subwavelength unit cell (with a thickness of λ/19) which consists of two different multiple-cavity resonators embedded into a plate structure with a groove. The sound absorption of the wall exists in two working bands (IandII) below 600 Hz which are created by two different mechanisms. In addition to the band I created by a conventional resonance coupling of the two multiple-cavity resonators, it is worth noting that the band II is realized by a mutual resonance coupling between the resonators and groove structure. The fractional bandwidths of the bands I and II can reach about 34.1 and 10.4%, respectively. Furthermore, the application of the proposed ultrathin planar wall in the design of a barrier-free anechoic room with omnidirectional low-frequency dual-band sound absorption is further discussed in detail. The proposed planar wall has the advantages of ultrathin planar structure and omnidirectional low-frequency dual-band sound absorption, which provides diverse routes to design advanced sound-absorption structures in noise control and architectural acoustics.

Bayesian design of broadband multilayered microperforated panel absorbers.

In some noise control and architectural acoustics applications, nonfibrous, hygienic materials are desirable or even strictly required. In meeting such restrictive requirements, microperforated panel (MPP) sound absorbers represent a potential solution. Yet, they typically possess limited absorption bandwidth. Combining multiple MPPs into a multilayer system may broaden the absorption frequency ranges while maintaining high absorption. When increasing the overall absorption bandwidth, each additional MPP layer also increases the complexity of the design process because the design parameters are correspondingly increased by four per each additional layer. This paper applies a Bayesian inferential framework to the design of multilayer MPP absorbers with a parsimonious structural configuration, which penalizes the overlayered configurations. This Bayesian framework demonstrates that the practical design of multilayer MPP absorbers may be accomplished with two levels of model-based inference: model selection and parameter estimation. The design process proceeds inversely from a design target to design parameters, including the required number of MPP layers and their corresponding MPP parameters. This paper discusses the Bayesian design formulation, unified implementation of two levels of Bayesian inference, and experimental validation of a Bayesian design for a multilayered MPP absorber, which is able to meet the design target arising from practice.

Echoes in the capitol, echoes in history: architectural acoustics, media archaeology, and the infrapolitics of reverberation

ABSTRACT This paper explores the notion of infrapolitics as the political dimension of reverberation and architectural acoustics. This aim is approached through a media-archaeological counterreading of the history of poor acoustics in the former chamber of the US House of Representatives supplied by historian Emily Thompson, as well as through juxtaposition of other cases of reverberation envelopes from the history of architectural acoustics. A media archaeological approach to reverberation and architectural acoustics, it is argued, approaches infrapolitics as a speculative understanding of the effect of architectural acoustics on early American democracy, and of architectural acoustics on discourse in general.

On the 50th anniversary of ASTM E33, a history of ASTM International standards on building and environmental acoustics

This year marks the 50th anniversary of ASTM International Committee E33 on Building and Environmental Acoustics which combined all ASTM activity in these areas into one committee, though work on ASTM standards for measurement of sound absorption and transmission had started prior to 1950. This presentation will discuss the history of the committee and ASTM International standards in acoustics including the leadership that has made it possible.

My experience at threshold and the consultation process

I had the great opportunity to take part in the Acoustical Society of America’s (ASA) 2021Summer Undergraduate Research or Internship Experience in Acoustics (SURIEA) Program. The program was designed for underrepresented minority groups in order to introduce them to the field of acoustics. After a two-week crash course I was able to experience what it was like working in an architectural acoustic consultation firm and learn the extensive consultation process at Threshold. Not only that, but learning some of the programs, the methodology, skills, and purpose of Threshold as well. The impact of the program has certainly opened my eyes to the field of architectural acoustics, and how much work has to go into a project for the best possible outcome. In essence, I found the experience to be one of the most impactful I had in my life.

Modeling musician diffraction for artificially excited clarinet directivity measurements

Directivity measurements of musical instruments have many applications in musical, audio, and architectural acoustics. Typical measurement methods include artificially excited instruments and instruments played by live musicians. While recent advances in directivity measurement techniques enable higher resolutions for played instruments, the results are still limited in bandwidth and repeatability compared with directivity results from artificially excited instruments. However, artificially excited instruments typically neglect musician diffraction and absorption. This work compares possible approaches for representing musician diffraction in artificially excited clarinet measurements to improve their directivity results for room simulations or auralizations.

Teaching acoustics during a pandemic: Lab in a Box for experiments at home.

In March 2020 with the advent of COVID, emergency plans were put in place to deliver the Master's Course in Environmental and Architectural Acoustics entirely on-line. This was necessary as although the acoustics laboratory is large, it was deemed to be unsafe for face-to-face teaching due to a complete lack of ventilation in the anechoic and reverberation chambers. Hence, it was necessary to create an alternative for the 2020/21 delivery. In September 2020, it was decided that a "Lab in a Box" supported by on-line demonstrations and pre-recorded films would create the best alternative experience for the postgraduate students. The "Lab in a Box" allowed demonstrations to be replicated at home or in the garden using a Windows based calibrated measurement platform based on audio components. Examples of such laboratories included Fast and Slow Measurements, Noise Exposure, Noise Survey, Loudness, Reverberation Time, and Speech Intelligibility. The results showed that the students gained from more independence and increased flexibility in delivery, achieving very similar marks. This has opened up the possibility of increasing student numbers by reusing these alternative teaching strategies in the future.

Acoustics for architects: A potpourri of undergraduate and graduate level teaching styles, tools and in-course projects.

Acoustics is one of the basic environmental comfort factors both in indoor and outdoor spaces. Students of architecture need to confront this theoretical field at some phase of their education. The main focus of this study is to provide a discussion platform of tools and teaching styles in architectural acoustics education of future architects, by depicting approaches that can motivate students and provide them a long-lasting understanding of the phenomena. Accordingly, a long-term experience in acoustics classes with undergraduate and graduate level students, mainly from departments of architecture of two prominent Turkish universities, is exemplified. Course contents of architectural acoustics programs are described, different models and methods of teaching are discussed, and last, selected projects, specifically those having an academic output, are presented. The study also aims to highlight some techniques and approaches that can be employed in acoustics education with limited technological tools, simply by active inclusion of the design background and creative thinking of the architecture students in this applied research area.

Streamlining ASTM acoustical standards

ASTM E33, the Committee on Building and Environmental Acoustics, has decided to undertake a process to streamline and harmonize existing E33 standards. As the committee’s standards have developed over the decades, inconsistencies, omissions, and contradictions have wound their way into the standards due to cross-references among standards and revisions. Members of this committee volunteered to spearhead an effort to restructure the standards with the goal of making the standards easier to understand, simpler to use, and to facilitate future revision efforts. This paper summarizes the beginnings of this effort and steps being taken at this time.

Measured high-resolution directivities of guitar amplifiers

Guitar amplifiers comprise specialized powered loudspeakers with distinct configurations and directivity characteristics. Recently, the authors measured the directivities of six guitar amplifiers using a new measurement system. The system employs a rotating semicircular microphone array in an anechoic chamber, with 2522 unique microphone positions over a surrounding sphere (i.e., 5-deg resolution in both the polar and azimuthal angles). This presentation will describe the measurement and processing procedures and compare the measured results to those produced by theoretical directivity models. An online archival database provides easy access to the guitar amplifier data and other directivity data from the human voice, played musical instruments, and other sound sources. The data are available in several commonly used file formats and should provide valuable information for many applications, including spatial audio, architectural acoustics modeling, and microphone placement.