Measurement of sound intensity applied to the determination of radiated sound power

Burger, Julia; Merwe, G.J.J. van der; Zyl, B. G. van; Joffe, L.

doi:10.1121/1.1913440

Cited by 12 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(18) suggest that if a regular spherical basis function was used as the testing wave, then it would be possible to build a microphone 'tent' which was sensitive only to sound created from within it, thereby allowing the spatial radiation (or scattering) of sources to be characterized in situ. This ability to eliminate room effects is well known for standard measurements of radiated sound power using an enclosing surface of intensity samples [20]. However for source (or scattering) directivity measurements it has only been achieved with spherical double layer microphone arrays [14,21]; this work allows extension of that to other shaped enclosing surfaces.…”

Section: Design Of Microphone Arraysmentioning

confidence: 99%

An Energy Interpretation of the Kirchhoff-Helmholtz Boundary Integral Equation and its Application to Sound Field Synthesis

Hargreaves¹,

Lam²

2014

Acta Acustica united with Acustica

View full text Add to dashboard Cite

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 functions, which are used to encode the spatial sound-field, are orthonormal over a sphere and because loudspeaker proximity is not fully addressed. Recently, significant progress to lift this restriction has been made through the theory of sound field synthesis, which formalizes various spatial audio systems in a mathematical framework based on the single layer potential. This approach has shown many benefits but the theory, which treats audio rendering as a sound-soft scattering problem, can appear one step removed from the physical reality and also possesses frequencies where the solution is non-unique. In the time-domain Boundary Element Method approaches to address such non-uniqueness amount to statements which test the flow of acoustic energy rather than considering pressure alone. This paper applies that notion to spatial audio rendering by re-examining the Kirchhoff-Helmholtz integral equation as a wave-matching metric, and suggests a physical interpretation of its kernel in terms of common acoustic power flux density between waves. It is shown that the spherical basis functions (spherical harmonics multiplied by spherical Bessel or Hankel functions) are orthogonal over any arbitrary surface with respect to this metric. Finally other applications are discussed, including design of high-order microphone arrays and the coupling of virtual acoustic models to auralization hardware.

show abstract

Section: Design Of Microphone Arraysmentioning

confidence: 99%

An Energy Interpretation of the Kirchhoff-Helmholtz Boundary Integral Equation and its Application to Sound Field Synthesis

Hargreaves¹,

Lam²

2014

Acta Acustica united with Acustica

View full text Add to dashboard Cite

show abstract

“…[3][4][5][6][7][8][9][10] Recently, efforts in this area have concentrated on the development of measurement techniques and devices. With the advent of new signal processing techniques and advances in transducer technology, intensity measurement devices have been improved to make them more reliable, accurate, and compact.…”

Section: Introductionmentioning

confidence: 99%

Development of an accelerometer-based underwater acoustic intensity sensor

Kim¹,

Gabrielson²,

Lauchle³

2004

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

An underwater acoustic intensity sensor is described. This sensor derives acoustic intensity from simultaneous, co-located measurement of the acoustic pressure and one component of the acoustic particle acceleration vector. The sensor consists of a pressure transducer in the form of a hollow piezoceramic cylinder and a pair of miniature accelerometers mounted inside the cylinder. Since this sensor derives acoustic intensity from measurement of acoustic pressure and acoustic particle acceleration, it is called a p-a intensity probe. The sensor is ballasted to be nearly neutrally buoyant. It is desirable for the accelerometers to measure only the rigid body motion of the assembled probe and for the effective centers of the pressure sensor and accelerometer to be coincident. This is achieved by symmetric disposition of a pair of accelerometers inside the ceramic cylinder. The response of the intensity probe is determined by comparison with a reference hydrophone in a predominantly reactive acoustic field.

show abstract

Sound Intensity, Measurements and Determination of Sound Power, Noise Source Identification, and Transmission Loss

2020

Engineering Acoustics

View full text Add to dashboard Cite

Measurement of sound intensity applied to the determination of radiated sound power

Abstract: A system for measuring sound intensity is described which can also be used for measuring very low sound levels.

Cited by 12 publications

References 0 publications

An Energy Interpretation of the Kirchhoff-Helmholtz Boundary Integral Equation and its Application to Sound Field Synthesis

An Energy Interpretation of the Kirchhoff-Helmholtz Boundary Integral Equation and its Application to Sound Field Synthesis

Development of an accelerometer-based underwater acoustic intensity sensor

Sound Intensity, Measurements and Determination of Sound Power, Noise Source Identification, and Transmission Loss

Contact Info

Product

Resources

About