手法を比較

	部屋のインパルス応答	音響ホログラフィ	音線追跡（Acoustic Ray Tracing）	Beamforming	BEM Acoustics
分野	音響学	音響学	音響学	音響学	音響学
系統	Process / pipeline	Process / pipeline	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1965	1985	1979	1988	1971
提唱者	Manfred Schroeder	James Maynard, Earl Williams, Yongjian Lee	James Allen, David Berkley	Van Veen, Barry Buckley	Carlos Brebbia, Robert Butterfield
種類	Measurement pipeline for room acoustics	Sound field reconstruction method	Computational room acoustics method	Directional audio array processing	Computational simulation for acoustics
原典	Schroeder, M. R. (1965). New method of measuring reverberation time. Journal of the Acoustical Society of America, 37(6), 409–412.	Maynard, J. D., Williams, E. G., & Lee, Y. (1985). Near-field acoustic holography: I. Theory of generalized holography and the development of NAH. Journal of the Acoustical Society of America, 78(4), 1395–1413.	Allen, J. B., & Berkley, D. A. (1979). Image method for efficiently simulating small-room acoustics. Journal of the Acoustical Society of America, 65(4), 943–950.	Van Veen, B. D., & Buckley, K. M. (1988). Beamforming: A versatile approach to spatial filtering. IEEE ASSP Magazine, 5(2), 4–24.	Burton, A. J., & Miller, G. F. (1971). The application of integral equation methods to the numerical solution of some exterior boundary-value problems. Proceedings of the Royal Society A, 323(1553), 201–210.
別名	RIR, impulse response measurement	NAH, near-field acoustics, sound field mapping, acoustic imaging	ray tracing, geometric acoustics, image source method, sound ray propagation	beamformer, spatial filtering, microphone array, phased array	BEM, boundary element method, indirect BEM, direct BEM
関連	5	5	5	5	5
概要	The Room Impulse Response (RIR) is a measure of how a physical space (room) affects acoustic signals propagating through it. First formalized by Manfred Schroeder in 1965, RIR captures the complete acoustic character of a space by measuring the system response to an impulsive sound source. It is fundamental to characterizing room acoustics, designing audio systems, and modeling spatial audio effects.	Near-Field Acoustic Holography (NAH) is a technique for reconstructing 3D acoustic sound fields and visualizing sound radiation from sources by measuring pressure at a dense microphone array in the near field. Pioneered by Maynard, Williams, and Lee in 1985, NAH extends holographic principles from optics to acoustics, enabling detailed acoustic source characterization, noise source identification, and acoustic field visualization that is impossible with conventional single-point or line-array methods.	Acoustic ray tracing is a computational technique for predicting sound propagation in rooms by treating acoustic energy as rays that reflect specularly off surfaces. Formalized by Allen and Berkley in 1979 via the image source method, ray tracing is one of the most computationally efficient methods for room acoustic simulation, especially for early and mid-reflections. It is widely used in audio engineering, architectural acoustics, and interactive spatial audio for virtual environments.	Beamforming is a spatial signal processing technique that uses microphone arrays to selectively enhance sound from a desired direction while suppressing sounds from other directions. Formalized by Van Veen and Buckley in 1988, beamforming is fundamental to hands-free speech communication, hearing aids, sonar, radar, and spatial audio recording. It enables 'listening' with directional sensitivity despite using omnidirectional microphones, by exploiting time delays and phase differences between array elements.	The Boundary Element Method (BEM) is a numerical technique for solving acoustic wave equations in complex geometries. Unlike finite element methods (FEM) that mesh entire volumes, BEM discretizes only the acoustic boundaries (surfaces), reducing computational cost and memory. First applied to acoustics by Burton and Miller in 1971, BEM is widely used for predicting room acoustics, exterior noise radiation, and acoustic scattering without the need for volumetric meshing.