Computational studies of steady-state sound field and reverberant sound decay in a system of two coupled rooms
The acoustical properties of an irregularly shaped room consisting of two connected rectangular subrooms were studied. An eigenmode method supported by a numerical implementation has been used to predict acoustic characteristics of the coupled system, such as the distribution of the sound pressure in steady-state and the reverberation time. In the theoretical model a low-frequency limit was considered. In this case the eigenmodes are lightly damped, thusthey were approximated by normal acoustic modes of a hard-walled room. The eigenfunctions and eigenfrequencies were computed numerically via application of a forced oscillator method with a finite difference algorithm. The influence of coupling between subrooms on acoustic parameters of the enclosure was demonstrated in numerical simulations where different distributions of absorbing materials on the walls of the subrooms and various positions of the sound source were assumed. Calculation results have shown that for large differences in the absorption coefficient in the subrooms the effect of modal localization contributes to peaks of RMS pressure in steady-state and a large increase in the reverberation time.
- Institute of Fundamental Technological Research, Polish Academy of Sciences, PL-00-049, Warsaw, Poland, firstname.lastname@example.org
-  H. Kuttruff: Room acoustics, Applied Science Publishers, London, 1973.
-  P.M. Morse and R.H. Bolt: “Sound waves in rooms”, Rev. Mod. Phys., Vol. 16, (1994), pp. 69–150. http://dx.doi.org/10.1103/RevModPhys.16.69[Crossref]
-  M. Heckl: Reverberation. Modern Methods in Analytical Acoustics, Springer-Verlag, New York, 1992.
-  P.M. Morse and K.U. Ingard: Theoretical acoustics, Mc Graw-Hill, New York, 1968.
-  E.H. Dowell, G.F. Gorman III and D.A. Smith: “Acoustoelasticity: general theory, acoustic natural modes and forced response to sinusoidal excitation, including comparison to experiment”, J. Sound Vib., Vol. 52, (1977), pp. 519–542. http://dx.doi.org/10.1016/0022-460X(77)90368-6[Crossref]
-  C.F. Eyring: “Reverberation time measurements in coupled rooms”, J. Acoust. Soc. Amer., Vol. 2, (1931), pp. 181–206. http://dx.doi.org/10.1121/1.1915555[Crossref]
-  C.M. Harris and H. Feshbach: “On the acoustics of coupled rooms”, J. Acoust. Soc. Amer., Vol. 22, (1950), pp. 572–578. http://dx.doi.org/10.1121/1.1906653[Crossref]
-  L. Cremer and H.A. Müller: Principles and applications of room acoustics, Applied Science, London, 1978.
-  C. Thompson: “On the acoustics of a coupled space”, J. Acoust. Soc. Amer., Vol. 75, (1984), pp. 707–714. http://dx.doi.org/10.1121/1.390581[Crossref]
-  R.L. Weaver and O.I. Lobkis: “Anderson localization in coupled reverberation rooms”, J. Sound Vib., Vol. 231, (2000), pp. 1111–1134. http://dx.doi.org/10.1006/jsvi.1999.2725[Crossref]
-  J.S. Anderson, M. Bratos-Anderson and P. Donay: “The acoustics of a large space with a repetitive pattern of coupled rooms”, J. Sound Vib., Vol. 208, (1997), pp. 313–329. http://dx.doi.org/10.1006/jsvi.1997.1219[Crossref]
-  J.S. Anderson and M. Bratos-Anderson: “Acoustic coupling effects in St Paul’s Cathedral, London”, J. Sound Vib., Vol. 236, (2000), pp. 209–225. http://dx.doi.org/10.1006/jsvi.1999.2988[Crossref]
-  D.T. Bradley and L.M. Wang: “The effects of simple coupled volume geometry on the objective and subjective results from nonexponential decay”, J. Acoust. Soc. Amer., Vol. 118, (2005), pp. 1480–1490. http://dx.doi.org/10.1121/1.1984892[Crossref]
-  J.E. Summers, R.R. Torres, Y. Shimizu and B.L. Dalenbäck: “Adapting a randomized beam-axis-tracing algorithm to modeling of coupled rooms via late-part ray tracing”, J. Acoust. Soc. Amer., Vol. 118, (2005), pp. 1491–1502. http://dx.doi.org/10.1121/1.2000772[Crossref]
-  J.E. Summers, R.R. Torres and Y. Shimizu: “Statistical-acoustics models of energy decay in systems of coupled rooms and their relation to geometrical acoustics”, J. Acoust. Soc. Amer., Vol. 116, (2004), pp. 958–969. http://dx.doi.org/10.1121/1.1763974[Crossref]
-  A. Billon, V. Valeau, A. Sakout and J. Picaut: “On the use of a diffusion model for acoustically coupled rooms”, J. Acoust. Soc. Amer., Vol. 120, (2006), pp. 2043–2054. http://dx.doi.org/10.1121/1.2338814[Crossref]
-  O.C. Zienkiewicz: The finite element method in engineering sciences, Mc Graw-Hill, London, 1977.
-  V. Easwaran and A. Craggs: “On futher validation and use of the finite element method to room acoustics”, J. Sound Vib., Vol. 187, (1995), pp. 195–212. http://dx.doi.org/10.1006/jsvi.1995.0515[Crossref]
-  C.A. Brebbia, J.C.F. Telles and L.C. Wrobel: Boundary element techniques, Springer, New York, 1984.
-  Y. Hobiki, K. Yakubo and T. Nakayama: “Spectral characteristics in resonators with fractal boundaries”, Phys. Rev. E, Vol. 54, (1996), pp. 1997–2004. http://dx.doi.org/10.1103/PhysRevE.54.1997[Crossref]
-  B. Sapoval and Th. Gobron: “Vibrations of strongly irregular or fractal resonators”, Phys. Rev. E, Vol. 47, (1993), pp. 3013–3024. http://dx.doi.org/10.1103/PhysRevE.47.3013[Crossref]
-  B. Sapoval, O. Haeberlé and S. Russ: “Acoustical properties of irregular and fractal cavities”, J. Acoust. Soc. Amer., Vol. 102, (1997), pp. 2014–2019. http://dx.doi.org/10.1121/1.419653[Crossref]
-  S.W. Kang and J.M. Lee: “Eigenmode analysis of arbitrarily shaped two-dimensional cavities by the method of point-matching”, J. Acoust. Soc. Amer., Vol. 107, (2000), pp. 1153–1160. http://dx.doi.org/10.1121/1.428456[Crossref]
-  M. Meissner: “Influence of wall absorption on low-frequency dependence of reverberation time in room of irregular shape”, accepted for publication in Appl. Acoust.. [WoS]
-  L.E. Kinsler and A.R. Frey: Fundamentals of acoustics, John Wiley & Sons, New York, 1962.
-  E.H. Dowell: “Reverberation time, absorption, and impedance”, J. Acoust. Soc. Amer., Vol. 64, (1978), pp. 181–191. http://dx.doi.org/10.1121/1.381983[Crossref]
-  S. Russ, B. Sapoval and O. Haeberlé: “Irregular and fractal resonators with Neumann boundary conditions: density of states and localization”, Phys. Rev. E, Vol. 55, (1997), pp. 1413–1421. http://dx.doi.org/10.1103/PhysRevE.55.1413[Crossref]
-  M. Meissner: “Influence of room geometry on low-frequency modal density, spatial distribution of modes and their damping”, Arch. Acoust., Vol. 30 (Supplement), (2005), pp. 203–208.
-  K.S. Sum: “Some comments on Sabine absorption coefficient”, J. Acoust. Soc. Amer., Vol. 117, (2005), pp. 486–489. http://dx.doi.org/10.1121/1.1810237[Crossref]
-  B. Harrison and G. Madaras: “Computer modeling and prediction in the design of coupled volumes for a 1000-seat concert hall at Goshen College, Indiana”, 141st Meeting of the Acoustical Society of America, J. Acoust. Soc. Amer., Vol. 109, (2001), p. 2388.
-  M. Ermann and M. Johnson: “Pilot study: Exposure and materiality of the secondary room and its impact on the impulse response of coupled-volume concert halls”, 143st Meeting of the Acoustical Society of America, J. Acoust. Soc. Amer., Vol. 111, (2002), p. 2331.
-  M. Barron: “Interpretation of early decay times in concert auditoria”, Acustica, Vol. 81, (1995), pp. 320–331.