A framework for auralization of boundary element method simulations including source and receiver directivity (2019)
Journal Article
Hargreaves, J., Rendell, L., & Lam, Y. (2019). A framework for auralization of boundary element method simulations including source and receiver directivity. ˜The œJournal of the Acoustical Society of America (Online), 145(4), 2625-2637. https://doi.org/10.1121/1.5096171

The Boundary Element Method (BEM) is a proven numerical prediction tool for computation of room acoustic transfer functions, as are required for auralization of a virtual space. In this paper it is validated against case studies drawn from the ‘Groun... Read More about A framework for auralization of boundary element method simulations including source and receiver directivity.

The wave-matching boundary integral equation - an energy approach to Galerkin BEM for acoustic wave propagation problems (2018)
Journal Article
Hargreaves, J., & Lam, Y. (2019). The wave-matching boundary integral equation - an energy approach to Galerkin BEM for acoustic wave propagation problems. Wave Motion, 87, 4-36. https://doi.org/10.1016/j.wavemoti.2018.07.003

In this paper, a new Boundary Integral Equation (BIE) is proposed for solution of the scalar Helmholtz equation. Applications include acoustic scattering problems, as occur in room acoustics and outdoor and underwater sound propagation. It draws toge... Read More about The wave-matching boundary integral equation - an energy approach to Galerkin BEM for acoustic wave propagation problems.

The influence of headphones on the localization of external loudspeaker sources (2015)
Journal Article
Satongar, D., Pike, C., Lam, Y., & Tew, A. (2015). The influence of headphones on the localization of external loudspeaker sources. Journal of the Audio Engineering Society, 63(10), 799-810. https://doi.org/10.17743/jaes.2015.0072

When validating systems that use headphones to synthesize virtual sound sources, a direct comparison between virtual and real sources is sometimes needed. This paper considers the passive influence of headphones on the sound transmission and percep... Read More about The influence of headphones on the localization of external loudspeaker sources.

Workshop on numerical acoustic simulation and auralisation as built environment design consultation tools (2015)
Journal Article
Hargreaves, J., & Lam, Y. (2015). Workshop on numerical acoustic simulation and auralisation as built environment design consultation tools. Acoustics bulletin / Institute of Acoustics, Nov 15,

Extended version of an article appearing in the November 2015 issue of Acoustics Bulletin, the UK Institute of Acoustics magazine. Describes an EPSRC-funded workshop, which was co-hosted by Arup and the University of Salford. For more informatio... Read More about Workshop on numerical acoustic simulation and auralisation as built environment design consultation tools.

Potential-based methodology for active sound control in three dimensional settings (2014)
Journal Article
Lim, H., Utyuzhnikov, S., Lam, Y., & Kelly, L. (2014). Potential-based methodology for active sound control in three dimensional settings. ˜The œJournal of the Acoustical Society of America (Online), 136(3), 1101-1111. https://doi.org/10.1121/1.4892934

This paper extends a potential-based approach to active noise shielding with preservation of wanted sound in three-dimensional settings. The approach, which was described in a previous publication [Lim et al., J. Acoust. Soc. Am. 129(2), 717–725 (201... Read More about Potential-based methodology for active sound control in three dimensional settings.

An energy interpretation of the Kirchhoff-Helmholtz boundary integral equation and its application to Sound Field synthesis (2014)
Journal Article
Hargreaves, J., & Lam, Y. (2014). An energy interpretation of the Kirchhoff-Helmholtz boundary integral equation and its application to Sound Field synthesis. Acta acustica united with Acustica, 100(5), 912-920. https://doi.org/10.3813/AAA.918770

Most spatial audio reproduction systems have the constraint that all loudspeakers must be equidistant from the listener, a property which is difficult to achieve in real rooms. In traditional Ambisonics this arises because the spherical harmonic func... Read More about An energy interpretation of the Kirchhoff-Helmholtz boundary integral equation and its application to Sound Field synthesis.

Multi-domain active sound control and noise shielding (2011)
Journal Article
Lim, H., Utyuzhnikov, S., Lam, Y., & Turan, A. (2011). Multi-domain active sound control and noise shielding. ˜The œJournal of the Acoustical Society of America (Online), 129(2), 717-725. https://doi.org/10.1121/1.3531933

This paper describes an active sound control methodology based on difference potentials. The main feature of this methodology is its ability to automatically preserve “wanted” sound within a domain while canceling “unwanted” noise from outside the do... Read More about Multi-domain active sound control and noise shielding.

Experimental validation of the active noise control methodology based on difference potentials (2009)
Journal Article
Lim, H., Utyuzhnikov, S., Lam, Y., Turan, A., Avis, M., Ryaben'kii, V., & Tsynkov, S. (2009). Experimental validation of the active noise control methodology based on difference potentials. AIAA journal, 47(4), 874-884. https://doi.org/10.2514/1.32496

To achieve active noise cancellation over a large area, it is often necessary to get a measure of the physical properties of the noise source to devise a counter measure. This, however, is not practical in many cases. A mathematical approach, the Dif... Read More about Experimental validation of the active noise control methodology based on difference potentials.

An analytical model for turbulence scattered rays in the shadow zone for outdoor sound propagation calculation (2009)
Journal Article
Lam, Y. (2009). An analytical model for turbulence scattered rays in the shadow zone for outdoor sound propagation calculation. ˜The œJournal of the Acoustical Society of America (Online), 125(3), 1340-1350. https://doi.org/10.1121/1.3076928

In outdoor sound propagation, an inherent problem of the ray tracing method is its inability to determine the sound pressure level in the shadow zone, where geometrical rays do not penetrate. This is a serious problem in a turbulent atmosphere where... Read More about An analytical model for turbulence scattered rays in the shadow zone for outdoor sound propagation calculation.

Sound fields near building facades: comparison of finite and semi-infinite reflectors on a rigid ground plane (2009)
Journal Article
Hopkins, C., & Lam, Y. (2009). Sound fields near building facades: comparison of finite and semi-infinite reflectors on a rigid ground plane. Applied Acoustics, 70(2), 300-308. https://doi.org/10.1016/j.apacoust.2008.03.008

The sound field in front of, and close to a building facade is relevant to the measurement and prediction of environmental noise and sound insulation. For simplicity it is often assumed that the facade can be treated as a semi-infinite reflector, how... Read More about Sound fields near building facades: comparison of finite and semi-infinite reflectors on a rigid ground plane.

Performance of T-shape barriers with top surface covered with absorptive quadratic residue diffusers (2008)
Journal Article
Monazzam, M., & Lam, Y. (2008). Performance of T-shape barriers with top surface covered with absorptive quadratic residue diffusers. Applied Acoustics, 69(2), 93-109. https://doi.org/10.1016/j.apacoust.2006.10.006

A previous paper [Applied Acoustics 66 (2005) 709–730] has shown that adding a quadratic residue diffuser (QRD) to the top of a T-shape barrier can provide better barrier performance than an equivalent purely absorptive barrier. In here, we extend th... Read More about Performance of T-shape barriers with top surface covered with absorptive quadratic residue diffusers.

On the modeling of sound propagation over multi-impedance discontinuities using a semiempirical diffraction formulation (2006)
Journal Article
Lam, Y., & Monazzam, M. (2006). On the modeling of sound propagation over multi-impedance discontinuities using a semiempirical diffraction formulation. ˜The œJournal of the Acoustical Society of America (Online), 120(2), 686-698. https://doi.org/10.1121/1.2216905

Several approximate extensions of the semi-empirical De Jong model [ De Jong et al., J. Sound and Vib. 86, 23–46 (1983) ] are considered for the prediction of sound propagation over multiple impedance discontinuities. A limitation in the original for... Read More about On the modeling of sound propagation over multi-impedance discontinuities using a semiempirical diffraction formulation.

A profiled structure with improved low frequency absorption. (2006)
Journal Article
Wu, T., Cox, T., & Lam, Y. (2006). A profiled structure with improved low frequency absorption. ˜The œJournal of the Acoustical Society of America (Online), 110(6), 3064-3070. https://doi.org/10.1121/1.1412443

It is possible to obtain good absorption from Schroeder diffusers if suitable alterations to the design are made. Interestingly, previous work has shown that good absorption appears possible below the design frequency when the diffusers are poorly co... Read More about A profiled structure with improved low frequency absorption..

Performance of profiled single noise barriers covered with quadratic residue diffusers (2005)
Journal Article
Monazzam, M., & Lam, Y. (2005). Performance of profiled single noise barriers covered with quadratic residue diffusers. Applied Acoustics, 66(6), 709-730. https://doi.org/10.1016/j.apacoust.2004.08.008

The paper describes an investigation about the acoustic performance of noise barriers with quadratic residue diffuser (QRD) tops, and with T-, Arrow-, Cylindrical and Y-shape profiles. A 2D boundary element method (BEM) is used to calculate the barri... Read More about Performance of profiled single noise barriers covered with quadratic residue diffusers.

Issues for computer modelling of room acoustics in non-concert hall settings (2005)
Journal Article
Lam, Y. (2005). Issues for computer modelling of room acoustics in non-concert hall settings. Acoustical science and technology, 26(2), 145-155. https://doi.org/10.1250/ast.26.145

The basic principle of common room acoustics computer models is the energy-based geometrical room acoustics theory. The energy-based calculation relies on the averaging effect provided when there are many reflections from many different directions, w... Read More about Issues for computer modelling of room acoustics in non-concert hall settings.

A boundary element method for the calculation of noise barrier insertion loss in the presence of atmospheric turbulence (2004)
Journal Article
Lam, Y. (2004). A boundary element method for the calculation of noise barrier insertion loss in the presence of atmospheric turbulence. Applied Acoustics, 65(6), 583-603. https://doi.org/10.1016/j.apacoust.2003.10.009

Atmospheric turbulence is an important factor that limits the amount of attenuation a barrier can provide in the outdoor environment. It is therefore important to develop a reliable method to predict its effect on barrier performance. The boundary el... Read More about A boundary element method for the calculation of noise barrier insertion loss in the presence of atmospheric turbulence.

The preferred initial time delay gap and inter-aural cross correlation for a Javanese gamelan performance hall (2002)
Journal Article
Sarwono, J., & Lam, Y. (2002). The preferred initial time delay gap and inter-aural cross correlation for a Javanese gamelan performance hall. Journal of Sound and Vibration, 258(3), 451-461. https://doi.org/10.1006/jsvi.2002.5268

This paper discusses the application of a method based on human subjective preference to the acoustic design of a Javanese gamelan performance hall. Some important distinctions between Javanese gamelan ensembles and Western classical orchestra are th... Read More about The preferred initial time delay gap and inter-aural cross correlation for a Javanese gamelan performance hall.

From a profiled diffuser to an optimized absorber (2000)
Journal Article
Wu, T., Cox, T., & Lam, Y. (2000). From a profiled diffuser to an optimized absorber. ˜The œJournal of the Acoustical Society of America (Online), 108(2), 643-650. https://doi.org/10.1121/1.429596

The quadratic residue diffuser was originally designed for enhanced scattering. Subsequently, however, it has been found that these diffusers can also be designed to produce exceptional absorption. This paper looks into the absorption mechanism of th... Read More about From a profiled diffuser to an optimized absorber.

Surface diffusion coefficients for room acoustics : free-field measures (2000)
Journal Article
Hargreaves, T., Cox, T., Lam, Y., & D'Antonio, P. (2000). Surface diffusion coefficients for room acoustics : free-field measures. https://doi.org/10.1121/1.1310192

A surface diffusion coefficient is needed in room acoustics to enable the quality of diffusing surfaces to be evaluated. It may also facilitate more accurate geometric room acoustic models. This paper concentrates on diffusion coefficients derived fr... Read More about Surface diffusion coefficients for room acoustics : free-field measures.

Subjective perception of seat dip attenuation (1996)
Journal Article
Davies, W., Cox, T., & Lam, Y. (1996). Subjective perception of seat dip attenuation. Acta acustica united with Acustica, 82(5), 784-792

An investigation has been conducted into the subjective perception of the seat dip effect (a low-frequency attenuation affecting sound travelling at grazing incidence over seating). In a realistic simulation of a concert hall sound field, the thresho... Read More about Subjective perception of seat dip attenuation.