U.P. Svensson

Norwegian University of Science and Technology | NTNU · Department of Electronic Systems

The validity of using a neural network to predict sound absorption coefficients of finite porous materials is tested with experimental data with a flush-mounted glass wool sample on a baffle. The network is pre-trained and validated with numerical simulations of flushed-mounted finite absorbers using a Delany-Bazley-Miki model. The experimental set...

A “rhythmic agent” is simulated based on the foundation of a previously published behavioral sensorimotor synchronization (SMS) model. The model is adjustable to control the auditory and tactile modalities of the tap's feedback. In addition to the conventional mechanisms of phase and period error correction, as well as their activation conditions,...

In multi-room environments, modelling the sound propagation is complex due to the coupling of rooms and diverse source-receiver positions. A common scenario is when the source and the receiver are in different rooms without a clear line of sight. For such source-receiver configurations, an initial increase in energy is observed, referred to as the...

This work proposes a method to predict the sound absorption coefficient of finite porous absorbers using a residual neural network and a single-layer microphone array. The goal is to mitigate the discrepancies between predicted and measured data due to the finite-size effect for a wide range of rectangular absorbers with varying dimensions and flow...

This work proposes a method to predict the sound absorption coefficient of finite porous absorbers using a residual neural network and a single-layer microphone array. The goal is to mitigate the discrepancies between predicted and measured data due to the finite-size effect for a wide range of rectangular absorbers with varying dimensions and flow...

Knowing the eigenfrequencies of a space is important for designing its acoustic performance at low frequencies. The eigenfrequencies can be analytically calculated for a limited set of room shapes, while for more complex domains it is common to use Finite Element methods (FEM). This paper investigates the use of Convolutional Neural Networks (CNN)...

The course "Acoustical Measurement Techniques TTT4250," offered by the Acoustics Group at the Department of Electronic Systems, Norwegian University of Science and Technology, is a fourth-year course in the specialization of acoustics in the five-year master program "Electronics Systems Design and Innovation" or MTELSYS, and the two-year internatio...

This study investigates effects of spatial auditory cues on human listeners' response strategy for identifying two alternately active talkers (“turn-taking” listening scenario). Previous research has demonstrated subjective benefits of audio spatialization with regard to speech intelligibility and talker-identification effort. So far, the deliberat...

In this paper we propose the use of neural networks to predict the sound absorption coefficient spectra of finite porous samples with microphone arrays. The main goal is to train a model that can effectively mitigate the errors caused by the finite size effect. A convolutional neural network architecture is used to map the array data to the absorpt...

Over the last decades, the applications of the active noise control system are broadened. In this study, the active noise control is modeled to reduce the noise pass through an open window. The objective is to define a suitable location for the control sources and error microphones to achieve more noise level reduction at the other side of the wind...

This paper presents a dynamic systems model of a sensorimotor synchronization (SMS) task. An SMS task typically gives temporally discrete human responses to some temporally discrete stimuli. Here, a dynamic systems modeling approach is applied after converting the discrete events to regularly sampled time signals. To collect data for model paramete...

While it is a well established discipline in academia with a broad range of applications, acoustics is usually not big enough a subject to exist at the department level of a university. Acoustics easily suffers from a lack of visibility in higher education, especially for young students at the start of university studies. Moreover, when the organiz...

When a marine seismic source, like an airgun, is fired close to the water surface the oscillating bubble interacts with the water–air interface. The main interest for seismic applications is how this effect impacts the acoustic signal propagating into the water. It is known that the sound transmission into air is abnormally strong when the sound so...

In this work, a technique to render the acoustic effect of scattering from finite objects in virtual reality is proposed, which aims to provide a perceptually plausible response for the listener, rather than a physically accurate response. The effect is implemented using parametric filter structures and the parameters for the filters are estimated...

A hybrid method for sound scattering calculations is presented in this paper. The boundary element method (BEM) is combined with a recently developed edge source integral equation (ESIE) [J. Acoust. Soc. Am. 133, 3681–3691 (2013)]. Although the ESIE provides accurate results for convex, rigid polyhedra, it has several numerical challenges, one of w...

The accurate prediction of sound radiation from unbaffled vibrating plates remains a challenging problem. Finite structures make the sound waves diffract off and around the edges, an effect which is particularly strong at low frequencies. This phenomenon can be modeled with an edge source integral equation (ESIE) [A. Asheim, U. P. Svensson, J. Acou...

Physical modeling of musical instruments is of great interest, both due to the interpretation of the parameters that make the model as similar to reality as possible, and because of the faithful sound synthesis. In this paper we will focus on the modeling of percussion instruments and more concretely drums consisting of a vibrating membrane and a r...

The scattering of sound by convex bodies with rigid surfaces can be modeled accurately without any wavenumber restriction using an edge source integral equation (ESIE) [A. Asheim and U. P. Svensson, J. Acoust. Soc. Am. 133 (2013) 3681-3691]. This edge diffraction-based approach has known limitations for non-convex scattering geometries, and the mos...

The sound radiation from unbaffled vibrating plates is a classical problem that is often solved numerically by coupling a vibration model to the surrounding air with the boundary element method, or the finite differences in the time domain (FDTD). Here, the surrounding air is instead represented with Green's functions computed with the edge source...

The scattering from rigid polyhedra can be efficiently and accurately modelled with an edge source integral equation. The modeling is based on a separation of the sound field into three terms: a geometrical-acoustics term, a term which represents first-order diffraction, and a term which represents second- and higher-order diffraction. It is the la...

The scattering from rigid polyhedra can be efficiently and accurately modelled with an edge source integral equation. The modeling is based on a separation of the sound field into three terms: a geometrical-acoustics term, a term which represents first-order diffraction, and a term which represents second- and higher-order diffraction. It is the la...

A hybrid method for acoustic scattering problems is studied in this paper. The boundary element method is combined with a recently developed edge diffraction based method [J. Acoust. Soc. Am. 133, pp. 3681-3691, 2013]. Although the edge diffraction method has been shown to provide accurate results for convex, rigid objects at a very attractive comp...

Currently, simulation of cone loudspeaker directivity is usually performed using Finite Element or Boundary Element methods, which can be slow and demanding on memory. This paper investigates the use of a mode matching method for simulating concave, axisymmetric geometries. The method is based on a method presented by Pagneux et al. [1] for simulat...

A hybrid method for acoustic scattering problems is studied in this paper. The boundary element method is combined with a recently developed edge diffraction based method [J. Acoust. Soc. Am. 133, pp. 3681–3691, 2013]. Although the edge diffraction method has been shown to provide accurate results for convex, rigid objects at a very attractive comp...

This paper reports the findings from a full-scale laboratory experiment about the assessment of architectural quality attributes in luminous environments. The presented data are part of the findings from a larger methodological experiment. This paper discusses the impact of window size and room reflectance on the perceived quality of a small room a...

The acoustical properties of two rooms that are one-way connected electroacoustically, e.g., in a telephone/video conference, can be analyzed through the total impulse response from a source in one room to the receiver in the other room. The total impulse response is a convolution of the two involved room impulse responses, and such a model is anal...

A method for simulating an expanding duct, like a horn, by mode matching techniques is described. For a horn in an infinite baffle, the modal radiation impedance and radiated pressure can be found from known relations. For a horn equipped with a small baffle or flange, however, diffraction from the edges has to be taken into account. This paper inv...

Computerized room acoustics modeling has been practiced for almost 50 years up to date. These modeling techniques play an important role in room acoustic design nowadays, often including auralization, but can also help in the construction of virtual environments for such applications as computer games, cognitive research, and training. This overvie...

Ground reflections cause problems when estimating the direction of arrival of aircraft noise. In traditional methods, based on the time differences between the microphones of a compact array, they may cause a significant loss of accuracy in the vertical direction. This study evaluates the use of first-order directional microphones, instead of omnid...

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Objective: The present study measured test-retest variability and time efficiency of an automated hearing assessment method called 'new early warning test (NEWT)' incorporated inside a quietpro (R) hearing protection device (HPD). Study design: Test-retest thresholds were obtained with manual pure tone audiometry (PTA) and automated NEWT method. Al...

Scitation is the online home of leading journals and conference proceedings from AIP Publishing and AIP Member Societies

In the presence of ground reflections, the traditional methods for aircraft noise direction of arrival estimation based on the time differences between the microphones of a compact array lose accuracy in the vertical angle. This paper studies the benefits of using a tetrahedral array geometry of first order directional microphones instead of omnidi...

This article presents the comparison analysis and results of an experiment designed with two presentation modes: real environments and stereoscopic images. The aim of this article is of a methodological nature, with a main objective of analyzing the usability of stereoscopic image presentation as a research tool to evaluate the daylight impact on t...

Manfred Schroeder and Bishnu Atal are behind two seminal conference presentations on room acoustics, one in 1962 and the other in 1967. In the first, computerized auralization was outlined remarkably early, long before the term auralization was introduced. In the second, a ray tracing technique in room acoustics was presented. Independently, Asbj½r...

This paper discusses the influence of the video stream on user’s audio quality preferences in quality evaluation of long duration episodes. The possible influence has been investigated under different presentation conditions. In addition, the impact of semantically consistent, long duration content on audio quality preferences is investigated. Obta...

Audio with good quality is the essential fundament for all multi-media services. The transmission of audio signals relies on efficient encoding and decoding algorithms (codecs) that enable the reduction of the required channel capacity, but still provide an excellent audio quality, even when transmission errors occur. The most succesfull audio code...

A new automated method termed as 'New Early Warning Test (NEWT)' has been designed to provide automatic auditory threshold monitoring in individuals exposed to high noise levels. The NEWT method is incorporated inside an active communication earplug called Quietpro®, which has high attenuation characteristics for background noise. The NEWT measures...

The secondary edge source line integral formulation for diffraction modeling uses edge sources with a 1/r dependency, in addition to a directivity function. At first sight, this might seem to contradict the expected 1/r behavior for the gradient near the edge of a thin screen. An analysis is presented for the special case of perpendicular plane wav...

A video conferencing situation combines the acoustical properties of two rooms. The resulting convolution of the two room impulse responses leads to a total impulse response with a reverberation, which is not a classical exponential decay. As a consequence, relationships between parameters such as clarity and reverberation time will be significantl...

In situations like video and teleconferencing, the acoustical properties of two rooms are involved via a convolution of the two room impulse responses. Reverberation in the two rooms will play quite different roles since the sender room reverberation will partially reach the listener, in the receiver room, from the source direction. Therefore, bina...

Exterior propagation of impulsive sound and its transmission through three-dimensional, thin-walled elastic structures, into enclosed cavities, are investigated numerically in the framework of linear dynamics. A hybrid model was developed in the time domain by combining the advantages of two existing numerical tools: (i) exterior sound propagation...

A formulation of the problem of scattering from obstacles with edges is presented. The formulation is based on decomposing the field into geometrical acoustics, first-order, and multiple-order edge diffraction components. An existing secondary-source model for edge diffraction from finite edges is extended to handle multiple diffraction of all orde...

Edge diffraction can be introduced into geometrical acoustics mainly by three models: detour-based, energetic and wave-based diffraction models. In the past, we thoroughly compared Maekawa's detour law, the uncertainty relation based diffraction method and the secondary source model by the example of edge diffraction of a single wedge. However, the...

In computer simulations of sound in enclosures, diffraction components can be added to geometrical acoustics ones for increased accuracy. A computational problem with diffraction is the large number of higher-order terms that is generated. A recent frequency-domain edge source integral equation (ESIE) efficiently handles the sum of all higher-order...

The sound field in open cavities with sloping walls can be represented by image sources and edge diffraction components. Sloping walls will generate a systematic structure to the positions of the image source, and explicit expressions for those positions are presented here. Using such explicit expressions, rather than the general image source metho...

Ground reflections complicate the acoustic estimation of the direction of an airborne sound source when using time difference of arrival techniques. In Ref. [1] a microphone array is presented for that purpose. This array differs from previous designs [2–5] in that it uses virtual directional microphones instead of omnidirec- tional microphones, in...

Teleconferencing applications often use a microphone placed directly on the table surface. A boundary or pressure zone microphone has its membrane mounted so close to a sound-reflecting plane that the membrane receives direct and reflected sounds in phase at all frequencies of interest, thereby avoiding destructive phase interference. However, in t...

While there has been great progress in inventing complex algorithms to evaluate room acoustics of large spaces, simple statistical models remain attractive because they can describe the space with a few parameters. This paper explores how Barron’s model can be used to investigate the early and late energy parameters in small shoebox shaped rooms, w...

Using our novel methodology for quality evaluation of long duration multimedia content, the effect of the time dimension on quality ratings and user responses is investigated. Particularly, the influence of audio artifacts related to different compression rates on participants’ reactions to quality changes over extended periods of time is examined....

Using our novel methodology for quality evaluation of long duration multimedia content, the effect of the time dimension on quality ratings and user responses was investigated. We were particularly interested in checking how audio artifacts related to different compression rates influence participants' reactions to quality changes over extended per...

A new integral equation for the scattering from rigid, or pressure-release, convex polyhedra and disks is presented. It is based on edge diffraction as a complement to the geometrical acoustics components, and uses directional edge sources as unknowns in the frequency-domain integral equation. Comparisons with reference results show that the new me...

The simulation of sound propagation in room- and city-acoustics is carried out by many researchers, acoustic consultants and others all around the world. Different software tools have been designed for specific simulation demands but usually rely on the same basic material characterizations. Unfortunately, there is no standard for the storage of su...

In this paper, we propose a design method for 3-D higher order ambisonics (3-D HOA) encoding matrices which offers the possibility to impose spatial stop-bands in the directivity patterns of all the spherical-harmonic audio channels while keeping the transformed audio channels still compatible with the 3-D HOA reproduction sound format. This might...

In this paper a new methodology for the evaluation of perceived quality for long duration audiovisual content is presented. This method allows the investigation of unexplored dependencies between perceived quality and impairment variations over extended periods of time. Instead of providing quality scores on predefined rating scales, assessors are...

Pairs of subjects were placed in two acoustically isolated rooms clapping together under an influence of delay up to 68 ms. Their trials were recorded and analyzed based on a definition of compensation factor or CF. This parameter was calculated from the recorded observations for both performers as a discrete function of time and thought of as a me...

Hand-clapping experiments were performed by pairs of subjects under the influence of a delay up to 68ms in various acoustic environments. The mean tempo decreased close to linearly as function of the delay. During each sequence the tempo slowed down to a degree that increased with the delay but for delays shorter than about 15-23 ms, the tempo incr...

The most common methods for simulating room- and city-acoustics are based on the principle of Geometrical Acoustics (GA), where the sound field is decomposed into specular reflections and scattering components. Unfortunately, edge diffraction is not directly covered by this simplified model of wave propagation, but several approaches exist to add t...

In telephone and video conferencing situations, the transfer function from a talker to a listener involves two rooms, one microphone and one loudspeaker. The room and the electroacoustical factors affect the speech quality for the listener, and this influence has been studied in this paper. Experiments were carried out with a loudspeaker playing ba...

In this paper, a three-dimensional optimal higher-order Ambisonics encoding (3-D HOA) method, which offers the possibility to impose spatial stop-bands in the directivity patterns of all the spherical harmonics while keeping the transformed audio channels still compatible with the 3-D HOA reproduction sound format, is introduced. This might be usef...

In loudspeaking teleconferencing applications, the impulse response from a talker in one room to a listener in the other room involves a convolution of two room impulse responses (RIRs). Here, such a system is analyzed using simple RIR models with a direct sound component plus a white Gaussian noise which is weighted by an exponential window. Expec...

Propagation of impulsive sound around buildings and induced structural loading are investigated experimentally and numerically. Experiments were conducted on a rectangular building at Virginia Tech using sonic booms generated by an explosive technique. Assuming linear-acoustic propagation and acoustically rigid surfaces, these experiments were simu...

Most of the existing spherical array modal beamformers are implemented in the frequency domain, where a block of snapshots is required to perform the discrete Fourier transform. In this paper, an approach to real-valued time-domain implementation of the modal beamformer for broadband spherical microphone arrays is presented. The microphone array da...

A robust minimum sidelobe beamforming approach based on the spherical harmonics framework for spherical microphone arrays is proposed. It minimizes the peaks of sidelobes while keeping the distortionless response in the look direction and maintaining the mainlobe width. A white noise gain constraint is also derived and employed to improve the robus...

The performance of conventional spherical microphone array modal beamformers is known to degrade in the presence of array errors. White noise gain control has been widely used to control the robustness of modal beamformers, but it is not clear how to properly choose the white noise gain parameters based on the level of array errors. In this paper,...

The field resulting from propagating sound interacting with a wedge is often decomposed into geometrical-acoustics (GA) and diffracted components. With such a decomposition, singularities in mathematical expressions for the latter typically are explained as necessary to compensate for discontinuities in the GA field at the two shadow boundaries and...

A benchmark project called “A Benchmarking Framework for Wave‐Based Computational Methods” was run in Japan, 2003–2005, coordinated by Tetsuya Sakuma, University of Tokyo, and with a few European participants. The project defined a number of interior and exterior (scattering) cases, ranging from very simple shapes to more realistic cases. A web sit...

This paper will give a brief overview of some alternatives for including diffractioneffects in computational room acoustics. Geometrical acoustics is the basis for most computer modeling methods in room acoustics, and both deterministic and stochastic approaches are used. The image source method and the beam tracing method dominate for the former,...

An approach to optimal array pattern synthesis based on spherical harmonics is presented. The array processing problem in the spherical harmonics domain is expressed with a matrix formulation. The beamformer weight vector design problem is written as a multiply constrained problem, so that the resulting beamformer can provide a suitable trade-off a...

The scattering from a rigid polyhedron can be decomposed into specular reflections and edge diffraction components. A secondary-source model exists which generates diffraction waves via sources along all edges of the polyhedron, also handling multiple diffraction. The previously presented formulation lead to an exponential growth in computation tim...

In this paper, we propose a convex optimization method for the design of 3-D High Order Ambisonics (3-D HOA) encoding matrices using spherical microphone arrays, which offers the possibility to impose spatial stop-bands in the directivity patterns of all the spherical harmonics while keeping the transformed audio channels still compatible with the...

A unified approach for designing spherical microphone arrays modal beamformers is proposed. Based on the elegant spherical harmonics framework, several commonly used convex performance parameter constraints, such as the directivity control constraint, the sidelobe level control constraint, and the robustness control constraint, can be derived. Usin...

For the problem of edge diffraction from an edge of finite length a frequency-domain solution, obtained from an analytical time-domain solution, has been presented by Svensson et al. [Acta. Acust. Acust. 95, 568-572]. This formulation takes the form of a Fourier-type integral whose evaluation is expensive in the high frequency range. This paper dem...

Until today, all known simulation methods for the wave phenomenon of edge diffraction are just approximations, based on either Geometrical Acoustics or the numerical solving of the wave equation. Although these methods work fine for simple test scenarios and a certain frequency range, they fail to simulate the effect of diffraction in its whole com...

A space domain optimal beamforming approach for spherical microphone arrays is presented, which is based on original microphone signals rather than spherical harmonics. A simple correlated multipath signal model is employed. The beamforming optimization criteria, including adaptive beamforming, multi-beam steering, sidelobe control, correlated inte...

Spherical array modal beamforming has become an attractive technique, since three-dimensional beampatten synthesis is more flexible than other array geometries, and the modal beamforming can be performed using the elegant spherical harmonics framework. However, the performance of a modal beamformer in practical situations is known to degrade in the...

We propose an optimal minimum sidelobe modal beamforming approach based on the spherical harmonics decomposition for spherical sensor arrays, which provide the ability of three-dimensional broad-band beampattern synthesis. The spherical harmonics domain array processing problem is expressed with a matrix formulation. The weight vector design proble...

The maximum-directivity beamformers, or the so-called plane wave decomposition (PWD) beamformers have been widely studied and used for spherical microphone arrays, but they are known to be sensitive to random array errors that exist in practical applications. In this paper, a robust maximum-directivity beamforming approach based on the spherical ha...

A human-computer interactive subjective test was arranged in which 12 users took part in a sensorimotor synchronization experiment. Their task was to follow a suddenly changing metronome by hand-clapping and finger-tapping, trying to adopt to the suddenly changing tempo. Up-sampled recorded trials with different interpolation methods were used to m...

This paper studies the strategy taken by a pair of ensemble performers under the influence of delay. A general quantifiable measure of strategy taken by performers in an interactive rhythmic performance is represented in a form of a single-parameter strategy function. This is done by imposing an assumption about a decision-making process for "onset...

A simplified prediction model for the early-to-late energy ratio has been tested for small rooms that are typically used in video conferences. The prediction model is a modified diffuse-field model, using Barron's revised formula for a distance-dependent reverberation level, together with Vorländer's revised formula for a constant reverberation lev...

A spherical harmonics domain microphone array beamforming approach is proposed. It unifies 3D multi-beam forming with tractable mainlobe levels, automatic multi-null steering, sidelobe control, and robustness control into one optimization framework, using a single spherical microphone array. The optimum array weights are designed by maintaining dis...

This paper proposes a methodology for the development of a computational quality model for IP-based audio. The project mainly focuses on two questions: 1) choice of a quality measurement scale in the computational model and mapping of this scale with existing audio quality measurement metrics, and 2) quantification of encoding and packet loss impai...

When Higher Order Ambisonics (HOA) is used to represent a sound field, the channels might contain a lot of redundancy in some cases. This redundancy can be exploited in order to provide more efficient network transmission and storage. In this work the amount of inter-channel redundancy for Higher Order Ambisonics is investigated. Furthermore, lossl...

Acoustic simulations of complex virtual environments typically are created with geometrical-acoustics techniques. Such simulations can be augmented with edge diffraction modeling for improved accuracy, but not without a significant increase in processing time due to the additional propagation paths which must be considered and the computational com...

A new frequency-domain, line integral formulation for the diffraction from a wedge insonified by a point source is discussed. This new method uses the physical coordinate along the edge as integration variable, which implies that finite edges can be handled directly by adjusting the integration range. Any internal or external scattering problem wit...

The effect of steady-state suppression (SSS) in situations where listeners hear natural and electroacoustical sounds, was investigated. The study found out that how multiple sound source listeners hear, how loudspeaker gain, and how the input to the PA system affect the performance of SSS. The listening test on young people with normal hearing usin...

Auditorium designs can be evaluated prior to construction by numerical modeling of the design. High-accuracy numerical modeling produces the sound pressure on a rectangular grid, and subjective assessment of the design requires auralization of the sampled sound field at a desired listener position. This paper investigates the production of binaural...

Auditorium designs can be evaluated prior to construction by numerical modeling of the design. Subjective assessment of the design requires auralization of the computed soundfield at a desired listener position and the binaural format is dominant for representation of the soundfield. For high accuracy the modeling is based on solving the wave equat...

Frequency-domain edge diffraction from an infinite wedge insonified by a point source has been widely studied, with various analytical solutions dating back nearly a century. In this talk we present an alternative frequency-domain solution which can be used for finite as well as infinite edges. The expression, given as a line integral along the dif...