Cad room acoustics software

Advanced signal processing also allows the playback of binaural signals initially meant for headphones through loudspeakers. This technique is called crosstalk cancellation CTC [50]. Although this method is very sensitive and can introduce spectral coloration it provides a good spatial reproduction with only two loudspeakers and avoids the discomfort from wearing headphones [51].

Buildings , 2 4. Application 4. Acoustical Planning The implementation of the room acoustics simulation uses state-of-the-art methods which were validated over the last couple of years [10,34,52]. Given the limitations of all geometrical methods, e. The tool is therefore suitable for the classical planning process by acoustics consultants, e. The integration of the visualization of room acoustic parameters as well as the immediate audio feedback within the 3D modelling software enables to quickly develope, modify and demonstrate his acoustics-related concepts and ideas.

In this way the necessary time effort can be reduced. This holds especially true when auralizations e. It is also not uncommon today to use geometrical acoustics software for the prediction of sound propagation in outdoor scenarios. Room acoustics parameters are not of interest anymore, but the sound pressure level predictions is a useful indicator. In recent years, the idea of soundscapes gained popularity, aiming at urban sound design and concerning the health problems caused by noise.

The presented acoustics library has been used on several occasions in the past to auralize outdoor sound scenes, an example which included video rendering is shown in Figure Auralization of a dynamic outdoor scene. The RAVEN library was used to produce spatial 3D sound for multiple sources, such as cars, a guitar player, birds, etc.

Supporting Architectural Design Next to the acoustical planning done by acoutic consultants, the plug-in can directly used by an architect during the design process of a building. For example in the early design stage which is very critical because fundamentals of a construction are defined here. In this phase, without an acoustic consultant being involved yet , irreversible acoustical design mistakes might occur.

Figure 9 see Section 3. The SketchUp plug-in was used during the design process to monitor and control room acoustics parameters for three different use cases, which were supported using variable room acoustics through movable panels. Besides controlling and optimizing the room acoustics already in the early planning phase of buildings, the auralization framework is perfectly qualified to present design results to clients and the public in an imposing and natural way.

An example for this is the first sonic preview of the Montreux Jazz Lab opening in , which was exhibited at the Montreux Jazz Festival in This outstanding archive, which lately had been given UNESCO heritage status, comprises over h of video and audio recordings from more than concerts of renowned musicians.

Virtual concerts at different positions in the virtual Montreux Jazz Lab can be auralizted using an iPad application, as shown in Figure The implementation makes use of the SUC to interface between the SketchUp and its auralization module with the tablet as an external controller. It remotely controls the auralization through an SUC module. Teaching Room Acoustics A strong application of the presented plug-in simulation was found in education.

The tool makes it very easy to demonstrate the effect of architectural decisions on the resulting acoustics conditions. While primarily used in architectural and acoustics teaching the visualization plus auralization concept may be well placed in civil engineering, sound engineering and music courses, too.

No technical background is necessary to listen and understand or even demonstrate the effects of different rooms, source directivities, receiver positions, etc. The easy access of the software makes a short tutorial sufficient to get started. This factor also led to the practice to include hands-on sessions into the courses during which every student will operate the software on an own laptop.

It was observed that this learning model is well accepted by the participating students. The software bundle of SketchUp, SUV and SUA is successfully being used in university courses in different countries around the world It is freely available upon request. Please contact the authors. After around 30—60 min, the participants are usually able to work with interactive auralizations and require only minimal help from the instructor, in some cases even no help at all. At demonstrations and courses especially people with little experience in room acoustics are impressed by the interactive operation and the real-time sound output.

The plug-in turned out to be a useful tool to rise awareness and understanding for room acoustics and spatial hearing. Sound Reinforcement Systems A typical use case for available room acoustics simulators is the calculation of sound pressure levels in sound reinforcement applications.

Many loudspeaker manufacturers use simplified models to account for the room influence which may provide only very rough approximations especially for exceptional rooms. As the presented plug-in provides room acoustics prediction including processing of directional data of loudspeakers, it has the potential to be used for detailed planning of sound reinforcement systems, ranging from complex announcement installations to live concert public address systems.

Music and Sound Production A completely different application is found in sound engineering, e. In the process of multi-track mixing, an important step deals with the spatial placement of instruments. Up to now this is limited to the production of stereo mixes, which uses simple amplitude panning between two loudspeakers.

The ambitious engineer, however, often tries to give depth and a distance impression to elements of the mix. This is usually done by balancing direct-to-reverberance ratios and adjustments to the delay between direct sound and randomly set early reflections.

This process is much facilitated by employing the room acoustics auralization module, with a simple stereo microphone pattern used as receiver directivity provided in the library. Natural reverberation and spatial coding including offset in depth are easily arranged and realistic sounding.

Each channel is then represented by a sound source in the SketchUp scene view, which allows direct and intuitive modification of spatial placement and reverberation adjustments through room modeling. Export to Virtual Reality Systems Another field of application are virtual reality systems, which aim at representing reality and its physical attributes in an interactive computer-generated virtual environment.

Especially in architectural applications such as a virtual walk through a complex of buildings, auditory information helps to assign meaning to visual information. Today, top-class systems, such as immersive CAVE systems see Figure 16 , enable an all embracing multi-modal experience with a strong feeling of presence for the user. But also less expensive systems, such as stereoscopic beamers, high-resolution TV screens or virtual reality headsets in combination with a 3D audiovisual rendering system and a few of-the-shelf PCs, are already capable of presenting a quite realistic image of the simulated scene.

As for the visual representation, the most promising low-budget system is probably the Oculus Rift, which is a next-generation virtual reality headset designed for immersive gaming.

The headset features an HD screen and uses a combination of 3-axis gyros, accelerometers and magnetometers for a precise and fast tracking of head-movements Hz refresh rate. Conclusions and Outlook This paper describes state-of-the art methods for the prediction of room acoustics. These base on geometrical construction of reflection paths. The performance was maximized by code optimization and parallel processing through multi-threading.

The real-time features are accessible through these interfaces and were used to connect the library to a plug-in that was integrated into the popular 3D modeling software Trimble SketchUp. The plug-in extends the functionality of the 3D editor to include real-time acoustics processing. Acoustics control elements are seamlessly aligned in the SketchUp GUI along with its internal tools and menus.

Important room acoustical parameters are visualized directly inside the 3D model view window and are updated at real-time rates while the user works on the room model. Additionally the sound card is used to play 3D sound including reverberation that is calculated by the room acoustics library. The real-time in-place result visualization and audio feedback together with the seamlessly integrated controls of the plug-in provide a highly intuitive workflow and interactivity.

The resulting package forms a very versatile tool that attracts many users. Architects, acoustic consultants, as well as teachers, students and also sound engineers belong to the group of actual and potential users. By directly plugging into the 3D modeler the acoustics module integrates well into the workflow of an architect, who is able to run simulations without a deeper founded knowledge in acoustics and without being an expert user of the usually complex simulation programs. But the low entry level of the chosen software SketchUp also enables acoustic consultants and other people unfamiliar with 3D modeling to effectively work on their acoustic models.

The real-time plug-in has many applications, with some of them being outlined in this paper. They range from architectural design and acoustical planning over very successful examples in education up to artistic use in sound production. For the future it is planned to develop a base class for the plug-in on the 3D modeler side, so that implementations for different 3D editing software is easier to derive. However due to the different internal structures of these programs a lot of work has to be spent on the final implementation and maintenance.

Another feature that is missing in the current implementation is a convenient export option for the results of the visualization which would be useful for documentation and further evaluation. Most of the research at ITA is dedicated to academic studies of all facets of 3-D audio.

Conflicts of Interest The authors declare no conflicts of interest. References 1. Naylor, G. Treatment of early and late reflections in a hybrid computer model for room acoustics. Kleiner, M. Auralization—An overview. Audio Eng. A macroscopic view of diffuse reflection. Kuttruff, H. Gade, A. Chapter 9: Acoustics in Halls for Speech and Music.

Bork, I. Acta Acust. United Acust. Pelzer, S. Quality assessment of room acoustic simulation tools by comparing binaural measurements and simulations in an optimized test scenario. Van Mourik, J. Computer simulations in room acoustics—Concepts and uncertainties. Schroeder, M. Krokstad, A. Calculating the acoustical room response by the use of a ray tracing technique. Sound Vib. Kuttruff, K. Buildings , 2 Lokki, T.

An Efficient Auralization of Edge Diffraction. Petersburg, Russia, 1—3 June Peter, S. Computational Modelling and Simulation of Acoutic Spaces. Borish, J. Extension of the image model to arbitrary polyhedra.

Allen, J. Image method for efficiently computing small-room acoustics. Lambert, J. Cox, T. ISO —Acoustics—Measurement of room acoustic parameters.

International Standards Organisation, — MacLaverty, R. Room Acoustical Simulation Algorithms Compared. Audio Engineering Society Convention 93, Heinz, R. Binaural room simulation based on an image source model with addition of statistical methods to include the diffuse sound scattering of walls and to predict the reverberant tail.

Stephenson, U. Quantized pyramidal beam tracing—A new algorithm for room acoustics and noise immission prognosis. Funkhouser, T. Frequency- and Time-dependent Geometry for Real-time Auralizations. Siltanen, S. Geometry Reduction in Room Acoustics Modeling. Shtrepi, L.

Vitale, R. Schumacker, R. Teschner, M. Real-time auralization of dynamically changing virtual environments. Flanagan, D. Fundamentals of binaural technology. Moore, B. Blauert, J. The auditory representation in virtual reality. Lentz, T. Binaural technology for virtual reality. Pulkki, V. Zotter, F. Reproduction of Artificial-Head Recordings through Loudspeakers. Dynamic crosstalk cancellation for binaural synthesis in virtual reality environments. On the accuracy of edge diffraction simulation methods in Geometrical Acoustics.

Aretz, M. These interfaces define sets of domain equations, boundary conditions, initial conditions, predefined meshes, predefined studies with solver settings, as well as predefined plots and derived values. Meshing and solver settings are handled automatically by the software, with options for manual editing. In this way, it is easy to incorporate multiple physics into one acoustics model, and there are several multiphysics interfaces built into the Acoustics Module and accessible when combining with other add-on modules from the COMSOL product suite.

For modeling pressure acoustics, there are multiple user interfaces where the sound field is represented by a scalar pressure variable. The general-purpose interfaces, based on FEM, include the capability of solving in both the frequency and time domain.

For the transient case, nonlinear effects can be included and are based on the Westervelt equation. To efficiently solve large radiation and scattering problems, frequency-domain BEM is available that couples seamlessly with the finite-element-based interfaces, both acoustic and structural.

To efficiently solve large transient models, a specialized user interface based on the discontinuous Galerkin finite element method and a time-explicit solver is available. This interface can be coupled to the corresponding time-explicit interface for elastic and piezoelectric waves. Two highly specialized interfaces are available for quick high-frequency acoustics analysis in the frequency domain.

These interfaces are based on computing the Kirchhoff—Helmholtz integral and include one interface for scattering analysis and another interface for radiation analysis. This type of analysis can be used as a first step before moving on to a more computationally demanding analysis based on FEM or BEM. The Acoustics Module includes user interfaces for modeling the propagation of linear elastic waves in solids, porous, and piezoelectric materials. These interfaces readily couple to fluid domains using a set of built-in multiphysics couplings.

The solid mechanics interfaces have the capability of representing full elastodynamics and can be used for modeling elastic waves in solids in both the frequency and time domain. A port boundary condition is specifically implemented to model and handle various propagating modes in elastic waveguide structures. The poroelastic interfaces are used for modeling poroelastic waves in porous materials. These waves result from the complex two-way interaction between acoustic pressure variations in the saturating fluid and the elastic deformation of the solid porous matrix.

Two interfaces, based on a time-explicit discontinuous Galerkin formulation, can be used for modeling linear elastic waves in solid and piezoelectric domains. These interfaces can be coupled and are suited for modeling domains with several wavelengths efficiently.

In addition, these interfaces can be coupled with the time-explicit interfaces for pressure acoustics. For modeling detailed convected acoustics, or flow-borne noise, a number of aeroacoustics interfaces are available in both the frequency and time domain. These interfaces are used for simulating one-way interaction of a background fluid flow with an acoustic field. There are different physics interfaces that solve the governing equations under various physical approximations.

The linearized Navier—Stokes interfaces are used for solving for the acoustic variations in pressure, velocity, and temperature. The linearized Euler interfaces are used for computing the acoustic variations in density, velocity, and pressure in the presence of a stationary background mean flow that is well approximated by an ideal gas flow. Special boundary mode interfaces are available for computing propagating and nonpropagating modes in waveguides and ducts in the presence of a background flow.

For simplified analysis, interfaces for linearized potential flow can be used in both the time and frequency domains.

To model an unbounded computational domain, you can truncate it using so-called perfectly matched layers PMLs in both time and frequency domains. Alternative methods include using radiation boundary conditions or an exterior domain modeled using a boundary element method interface. For finite-element-based interfaces, an exterior field calculation feature can be used to determine the pressure in any point outside the computational domain.

Dedicated results and analysis capabilities exist for visualizing the radiation pattern of the exterior field near and far field in polar, 2D, and 3D plots. The computational method is based on the FEM discretization of Lighthill's acoustic analogy wave equation.

This formulation of the equations ensures that any solid fixed or vibrating boundaries are implicitly taken into account. The functionality relies on coupling an LES fluid flow simulation, using the CFD Module, to an aeroacoustic flow source for pressure acoustics, available in the Acoustics Module. There is a large variety of boundary conditions available for pressure acoustics, including hard walls and conditions for applying sources.

There are radiation, symmetry, periodic, and port conditions for modeling open boundaries. Impedance conditions include models for different parts of the human ear, human skin, simple RCL circuit models, and more. By using the interface for boundary mode analysis, you can study propagating modes in the cross sections of waveguides and ducts.

The options for modeling idealized sources include built-in options for monopole, dipole, and quadrupole point sources. The interfaces for acoustic—structure interaction apply to phenomena where the fluid pressure causes a load on the solid domain and the structural acceleration affects the fluid domain across the fluid—solid boundary. This is also known as vibroacoustics. The interfaces include the capability of solving in either the frequency or the time domain.

The solids included in the simulations can be isotropic, anisotropic, porous, or piezoelectric. By combining with the Structural Mechanics Module, the structural side of the coupling can additionally include structural shells or membranes.

By combining with the Multibody Dynamics Module, you can include the effects of multiple moving rigid or flexible parts connected through various types of joints. In order to accurately model acoustics in geometries with small dimensions, it is necessary to include thermal conduction effects and viscous losses explicitly in the governing equations. This capability is included in the interfaces for thermoviscous acoustics, which simultaneously models the effects of pressure, particle velocity, and acoustic temperature oscillations.

Near walls, there are viscous and thermal boundary layers. Here, viscous losses due to shear and thermal conduction become important because of large gradients.

For this reason, it is necessary to include thermal conduction effects and viscous losses explicitly in the governing equations. The REW room acoustics software contains comprehensive help information.

You can also view the help files online , download the html files for offline viewing Online help for the current beta version can be found in the Beta help files. John Mulcahy is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon. Room Acoustics Software REW is free software for room acoustic measurement, loudspeaker measurement and audio device measurement.

Downloads The current version is V5. If you are looking for V5.