Measurement of sound intensity

Pavić, Goran

doi:10.1016/s0022-460x(77)80050-3

Cited by 42 publications

(14 citation statements)

References 5 publications

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“…Although the finite difference approximation error in principle depends on the sound field, [5][6][7] practice has shown that the influence of the error on measurement of sound power can be conservatively predicted from the expression for intensity estimation in a plane wave with a direction that coincides with the axis of the probe, 1 Î r ϭI r sin k⌬r k⌬r , ͑1͒…”

Section: A the Finite Difference Approximationmentioning

confidence: 99%

“…Unfortunately the influence of several other measurement errors, of which the most well known and most serious is phase mismatch, is inversely proportional to the length of the spacer. 5,[8][9][10] This means that an intensity probe with smaller microphones separated by a shorter distance will have a higher lower limiting frequency. To this can be added that, quite apart from the influence of the separation distance, Another way of overcoming the relatively low upper frequency limit of the sound intensity technique might be to ''correct'' the finite difference error by multiplying with a factor of k⌬r/sin k⌬r, as suggested by Balant et al 11 However, this cannot be recommended in the general case; it tends to lead to overestimation because the intensity vector will usually not be perpendicular to the measurement surface used in sound power determination.…”

Section: K⌬rͻ115 ͑2͒mentioning

confidence: 99%

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A numerical and experimental investigation of the performance of sound intensity probes at high frequencies

Jacobsen

Cutanda

Juhl

1998

The Journal of the Acoustical Society of America

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The influence of scattering and diffraction on the performance of sound intensity probes has been examined using a boundary element model of an axisymmetric two-microphone probe with the microphones in the usual face-to-face arrangement. On the basis of calculations for a variety of sound field conditions and probe geometries it is concluded that the optimum length of the spacer between the microphones is about one microphone diameter; with this geometry the effect of diffraction and the finite difference error almost counterbalance each other up to about an octave above the frequency limit determined by the finite difference approximation. This seems to be valid under virtually any sound field condition that could be of practical importance in sound power determination. The upper frequency limit corresponds to about 10 kHz for an intensity probe with 12-in. microphones, which means that it should be possible to cover most of the audible frequency range, say, from 50 Hz to 10 kHz, with a single probe configuration. The numerical results have been confirmed by a series of experiments.

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Section: A the Finite Difference Approximationmentioning

confidence: 99%

Section: K⌬rͻ115 ͑2͒mentioning

confidence: 99%

A numerical and experimental investigation of the performance of sound intensity probes at high frequencies

Jacobsen

Cutanda

Juhl

1998

The Journal of the Acoustical Society of America

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“…It is used for sound power measurements, sound source locations, and visualizations of sound fields [1][2][3][4]. The time-averaged SI is suitable for the sound power measurement, whereas the envelope intensity is recommended for the analysis of transient sounds [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

“…The most common time-averaged and envelope intensity measurement methods are to use two (pressure) microphones (p-p probe) [1][2][3]. By use of the p-p probe, average sound pressure and particle velocity, and then timeaveraged and/or envelope intensities at the center of the pair microphones are obtained.…”

Section: Introductionmentioning

confidence: 99%

Numerical evaluation of three-dimensional sound intensity measurement accuracies and a proposal for an error correction method

Iino¹,

Tatekawa²,

Mizukawa³

et al. 2013

Acoust. Sci. & Tech.

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In the three-dimensional (3-D) sound intensity measurement using four-microphone probes, there are two well-known microphone arrangements. One is arranging four microphones at the vertexes of a regular tetrahedron and the other is arranging them at the nearest four corners of a cube. In the high frequency region, these 3-D probes suffer from the same type of sensitivity reductions as do 1-D p-p probes. In this paper, formulae to obtain three orthogonal intensity components for these two types of probes are reviewed first, and their sensitivity and leakage errors are numerically discussed not only for the along-the-axis plane wave incidences but also for incidences from various directions in the 4 space. This analysis reveals characteristic differences of measurement errors of the two types of probes. Since the sensitivity and leakage errors are systematic, it is possible to correct these errors (to some degree) using the source direction information given by a real (or a numerical) measurement. A new correction method is proposed, and the effectiveness of the method is evaluated numerically. Results show that the proposed method is very effective, and the high-end of the frequency range is widened close to the limit, at which the dimension of the 3-D probe is nearly equal to the half wavelength of the incident plane wave.

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“…The pressure can be estimated using a finite sum between two or more microphones and the velocity with a finite-difference calculation-a method known as the p-p technique. [1][2][3] This is in contrast to the p-u technique, wherein the particle velocity is measured directly. 4,5 With two microphones, the intensity can be estimated in one dimension, whereas with four or more microphones it is possible to get a complete threedimensional estimation.…”

Section: Introductionmentioning

confidence: 99%

Comparison of methods for processing acoustic intensity from orthogonal multimicrophone probes

Wiederhold

Gee

Blotter

et al. 2012

The Journal of the Acoustical Society of America

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One design for three-dimensional multimicrophone probes is the four-microphone orthogonal design consisting of one microphone at an origin position with the other three microphones equally spaced along the three coordinate axes. Several distinct processing methods have been suggested for the estimation of active acoustic intensity with the orthogonal probe; however, the relative merits of each method have not been thoroughly studied. This comparative study is an investigation of the errors associated with each method. Considered are orthogonal probes consisting of matched point sensor microphones both freely suspended and embedded on the surface of a rigid sphere. Results are given for propagating plane-wave fields for all angles of incidence. It is shown that the lowest error for intensity magnitude results from having the microphones in a sphere and using just one microphone for the pressure estimate. For intensity direction, the lowest error results from having the microphones in a sphere and using Taylor approximations to estimate the particle velocity and pressure.

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Measurement of sound intensity

Cited by 42 publications

References 5 publications

A numerical and experimental investigation of the performance of sound intensity probes at high frequencies

A numerical and experimental investigation of the performance of sound intensity probes at high frequencies

Numerical evaluation of three-dimensional sound intensity measurement accuracies and a proposal for an error correction method

Comparison of methods for processing acoustic intensity from orthogonal multimicrophone probes

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