4,532 research outputs found
Ten questions concerning computational urban acoustics
Get PDFAbstractThe sound environment in urban areas is complex, as caused by many sources of sound and influenced by a variety of acoustic propagation effects. In order to combat noise and create acoustic environments of high quality, it is of utmost importance to be able to predict the time dependent sound field in such areas. Engineering methods are useful for a fast analysis and noise mapping purposes, but remain tools with limitations. Besides, computational modelling of urban acoustics, i.e. the group of wave-based solution methods, has obtained its role for complex environments as well as for research purposes. These computational models have become more mature in the recent decade. This paper addresses questions that are of interest for all scientists and research-oriented engineers in this field, as well as researchers in related fields of urban physics. The questions relate to the need for computational methods, the relevance of including various urban propagation effects in computational modelling, and to the preferable computational methods and approaches to use. Answers are based on scientific work by the author and many other urban acoustic researchers, and will also contain visionary opinions of the author
The influence of Room Acoustic Aspects on the Noise Exposure of Symphonic Orchestra Musicians
No full textMusicians in a symphonic orchestra are exposed to the noise of a large number of different sound sources. The noise exposure can vary largely and has many aspects of influence. One group of aspects are musical aspects, like the orchestra size and composition, the musical piece and its interpretation by the conductor and orchestra. The other group of aspects are architectural and room acoustic related which may contribute to a variation in noise exposure, independent of the musical aspects to some extent. On one hand, the size of the stage or orchestra pit may determine the distance between the musicians, which typically influences the direct and early reflected sound paths. Besides that, the room acoustics of the stage and the hall can increase the noise exposure dramatically. In this research, the contribution of stage size and acoustics to the total noise exposure and instrument balance is investigated for 7 concert halls A to G as described by Luxemburg et al. [2009]
Sustainability in building acoustics
No full text13701373Sustainability in building acoustics is increasingly important in the architectural and construction industries, addressing the need for environmentally responsible design that enhances human comfort and ecological balance. As urbanization accelerates, managing noise pollution becomes crucial, leading to adverse health effects and reduced quality of life. This article explores the relationship between sustainability, acoustic performance, and costs in actual building practice. The study examines traditional acoustic design practices that often overlook the environmental impact of materials. By using sustainable materials, such as recycled resources, architects can minimize the ecological footprint while ensuring effective noise reduction. Innovative technologies like green facades and rapidly renewable materials provide solutions for enhancing acoustic comfort without compromising sustainability. Additionally, the article discusses building regulations that promote sustainable acoustics, encouraging stakeholders to prioritize noise management in their projects. It also questions why sustainable building systems are rarely used in modern construction despite growing social demand. The findings highlight the necessity of a holistic approach that considers both affordable acoustic and environmental performance. A commitment to sustainability in building acoustics contributes to healthier living environments and supports broader goals of reducing carbon emissions and conserving resources
Comparing Room Acoustics Simulation Tools: Dataset for Reproducing and Expanding the Results
No full textThis is the database connected to the paper Dijkman, L., Hoekstra, N. and Hornikx, M. Comparing Open-Source Room Acoustics Simulation Tools: Performance and Usabillity Insights (2025). This database contains the following information: Simplified room geometries for Complex Room 2 (CR2) and Complex Room 4 (CR4) from the Benchmark for Room Acoustical Simulation (BRAS). Material data (absorption, scattering and approximated reflection coefficients) for all materials in both rooms. Source and receiver positions (x, y, z) according to the simplified room models. All simulation results for the simulation tools used in the research. Scripts for post processing of the results. For an overview of all research on open-source simulation tools for room acoustics conducted by the TU/e Building Acoustics group, see: https://github.com/Building-acoustics-TU-Eindhoven/OSS_RoomAcoustics References @techReport{Aspo2020, author = {Lukas Aspöck and Michael Vorländer and Fabian Brinkmann and David Ackermann and Stefan Weinzierl}, doi = {10.14279/depositonce-6726.2}, institution = {RWTH Aachen}, keywords = {Room acoustic simulation,acoustic modeling,virtual acoustic}, title = {\{B\}enchmark for \{R\}oom \{A\}coustical \{S\}imulation (\{BRAS\}) - \{D\}ocumentation of the database}, year = {2020}} @article{Mond2020, author = {Boris Mondet and Jonas Brunskog and Cheol Ho Jeong and Jens Holger Rindel}, doi = {10.1016/j.apacoust.2019.04.034}, issn = {1872910X}, journal = {Applied Acoustics}, keywords = {Absorption coefficient,Inverse problem,Room acoustics,Surface impedance}, publisher = {Elsevier Ltd}, title = {\{F\}rom absorption to impedance: \{E\}nhancing boundary conditions in room acoustic simulations}, volume = {157}, year = {2020}} @inproceedings{Berz2017, author = {Marco Berzborn and Ramona Bomhardt and Johannes Klein and Jan-Gerrit Richter and Michael Vorländer}, booktitle = {DAGA}, title = {\{T\}he \{ITA\}-\{T\}oolbox: \{A\}n \{O\}pen \{S\}ource \{MATLAB\} \{T\}oolbox for \{A\}coustic \{M\}easurements and \{S\}ignal \{P\}rocessing}, year = {2017}
Project ancient acoustics part 3 of 4 : Influence of geometrical and material assumptions on ray-based acoustic simulations of two ancient theatres
Get PDFAcoustic models of ancient theatres found in literature are often based on assumptions, both for geometrical and material properties. The influences of these assumptions on modelling results have been assessed in this paper, which is part of the Ancient Acoustics project. Acoustical measurements were conducted in the Odeon of Herodes Atticus, the theatre of Epidaurus and the theatre of Argos, resulting in a large amount of high quality impulse responses per theatre. As part of the Ancient Acoustics project, 3D models were realised of the Odeon of Herodes Atticus and the theatre of Epidaurus to be used in the ray-based room acoustic simulation software 'Odeon'. To ensure the geometric accuracy of our models, measurements were performed with a Total Station theodolite in both theatres. A stepwise evaluation on the influence of the absorption and scattering coefficients is presented for the most accurate geometry using various plausible literature data. Next, the model material settings, for which the trends of simulated result were closest to the acoustic measurements, have been applied to both our own and literature based 3D models with various geometrical accuracies. The run-to-run deviations were taken into account and optimized settings were used, such as the number of rays and the transition order. Finally, the influence of the geometric deviations on selected acoustical parameters are evaluated and presented
Virtual Building Acoustics
No full textModern societies have concerns about growing annoyance due to noise in private dwellings and in commercial worksites. People are exposed to the noise from neighbours, adjacent offices and road traffic which causes disturbance in sleep, physical or mental work impairments. Though ISO (International Standards Organization) provides sound insulation guidelines to protect citizens from the noise exposures, these guidelines do not provide an optimal acoustic satisfaction especially for specific sounds, for example a conversation varying in intelligibility. This work addresses the challenges in traditional sound insulation models, filters and auralization techniques, and establishes an interface between psychoacoustic research and building acoustics in audio-visual VR environments. Improvements are made in sound insulation prediction methods, filters construction and rendering techniques for sound insulation auralization. The virtual building acoustic framework (VBA) is developed toward real-time interactive audio-visual technology, to be able to introduce more realism and, hence, contextual features into psychoacoustic experiments. Listening experiments close to real-life situations are carried which showed that the VBA can be used as an alternate to design test paradigms which help to better analyse and interpret the noise impacts in built-up environments situations depending on the actual activities
Transparant Concert Hall Acoustics
No full textApril 15, 2005 the new concert hall for symphonic music, Casa da Música in Porto, Portugal,
has been inaugurated. The architectural concept of a transparent shoebox-shaped hall in
combination with program requirements challenged the acoustics in many ways. By just
pressing a button the acoustics of the hall is changed from excellent for symphonic music to
adequate for amplified productions. All kind of technical provisions have been introduced in the
design: lighting bridges, movable canopy, acoustic curtains, a moving bridge etc. In fact we
believe a new type of multifunctional halls has been built. Will this be the future and, if so, what
are the consequences for the field of acoustics?
The main auditorium, with a capacity of 1250 seats, has a transparent vertically movable and
cantilever canopy. Canopy positions have been studied to optimize the support on the stage
with respect to the playing ensemble.
QRD diffusers have been applied to create a diffuse and equally distributed sound field.
Because of architectural issues the standard 734 diffusers have been modified. Instead of the 0-
deep well in the sequence 0–1–4–2–2–4–1, a 7–deep well is used. This modification proved to
have an impact on the acoustic performance of the diffusers, thus the acoustics of the hall
Meetonzekerheid in de akoestiek : werkwijze binnen ISO TC43 'Acoustics'
No full textTraditionally ISO standards concerning acoustical measurement methods include some information about the expected measurement accuracy of the method described. Since a number of years this type of information is treated in much more detail than before. In recently published standards an extensive annex about measurement uncertainty is included. Contradictory to the formerly used terminology the subject is no longer discussed in terms of the Repeatability and the Reproducibility, but in terms of the Standard Uncertainty and the Expanded Uncertainty. Also the Uncertainty Budget was introduced. This terminology is derived from the Guide to the expression of uncertainty in measurement (GUM), published by ISO and IEC. The basic principles of the approach according to the GUM will be discussed and the terminology will be clarified. In the second part of the paper the implementation of these principles in the field of building acoustics will be discussed and illustrated with examples of the current Dutch approach
A platform for benchmark cases in computational acoustics
Get PDFSolutions to the partial differential equations that describe acoustic problems can be found by analytical, numerical and experimental techniques. Within arbitrary domains and for arbitrary initial and boundary conditions, all solution techniques require certain assumptions and simplifications. It is difficult to estimate the precision of a solution technique. Due to the lack of a common process to quantify and report the performance of the solution technique, a variety of ways exists to discuss the results with the scientific community. Moreover, the absence of general reference results does hamper the validation of newly developed techniques. Over the years many researchers in the field of computational acoustics have therefore expressed the need and wish to have available common benchmark cases. This contribution is intended to be the start of a long term project, about deploying benchmarks in the entire field of computational acoustics. The platform is a web-based database, where cases and results can be submitted by all researchers and are openly available. Long-term maintenance of this platform is ensured. As an example of good practice, this paper presents a framework for the field of linear acoustic. Within this field, different categories are defined – as bounded or unbounded problems, scattering or radiating problems and time-domain as well as frequency-domain problems – and a structure is proposed how to describe a benchmark case. Furthermore, a way of reporting on the used solution technique and its result is suggested. Three problems have been defined that demonstrate how the benchmark cases are intended to be used
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