Application of the sound intensity technique to measurement of field sound transmission loss

Lai, J.C.S.; Burgess, Marion

doi:10.1016/0003-682x(91)90023-8

Cited by 11 publications

(13 citation statements)

References 10 publications

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“…The application of the sound intensity technique to field transmission loss m easurem ents of elem ents of com posite partitions is quite promising, as reported by Lai and Burgess (1991). Figure 9 shows schematically a room in a building site where the effect of applying different types of m aterial to the concrete blockwork can be assessed.…”

Section: Sound Transmission Loss Measurementsmentioning

confidence: 79%

Some Applications of the Sound Intensity Technique to Noise Control in the Workplace

Lai

1996

International Journal of Occupational Safety and Ergonomics

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Over a decade has elapsed since com m ercial sound intensity m easurem ent systems became available. A literature search has shown th a t the sound intensity technique has fou nd increasing applications in recent years. In this article, the principle and errors o f the sound intensity technique are briefly described. Four case studies are given to illustrate how the sound intensity technique can be applied to determ ine sound pow er under both laboratory and field conditions, to identify noise source and to measure sound transm ission loss o f com posite partitions "in situ." It has been shown that, provided the lim itations o f the sound intensity technique are understood, results obtained by the sound intensity technique enable effective noise control to be im plem ented in the workplace.sound intensity sound pow er sound transm ission loss noise source identification noise control

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Section: Sound Transmission Loss Measurementsmentioning

confidence: 79%

Some Applications of the Sound Intensity Technique to Noise Control in the Workplace

Lai

1996

International Journal of Occupational Safety and Ergonomics

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“…Data-data tersebut digunakan untuk menghitung koefisien serapan seperti pada pers. (5). Software yang digunakan untuk akuisisi data adalah visual analyzer 2011, sedangkan untuk pengolahan data digunakan sofware origin 7,5.…”

Section: Hasil Rancang Bangun Tabung Impedansi Dan Bahan Ujiunclassified

Rancang Bangun Alat Ukur Koefisien Serapan Akustik (Halaman 26 s.d. 30)

Alim¹

2014

J. Fis. Indones.

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Abstrak -Abstract -The instrument of acoustic absorption coefficient has been built in the Atomic and Nuclear Laboratory of Physics Department of the FMIPA UGM. The instrument was built works as an impedance tube that propagate the sound waves from the speaker to the source test material in normal directions, causing a standing wave in the tube. The magnitude of sound intensity that is formed in the tube was detected using three microphones, each of which is placed behind the sample, in the middle of the inner tube and in the middle of the outer tube. Impedance tube material used is PVC pipe. The instrument was used to measure the acoustic absorption coefficient of four different materials. .

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“…͑36͒. 15,16 As for the intensity, the finite difference errors are not taken into account here, and the measured impedance of Eq. ͑38͒ is expressed in terms of the estimated impedance from finite difference approximations.…”

Section: Consequences On the Impedance Measurementsmentioning

confidence: 99%

“…The active and reactive intensities can be used to determine the impedance of acoustic materials 15,16 and the radiation impedance of the sources. 17,18 The influence of the vents must be taken into consideration for these measurements, taken close to the sources or the materials, in sound fields with a large reactive component produced by the near field or the reflections.…”

Section: Consequences On the Impedance Measurementsmentioning

confidence: 99%

The influence of microphone vents on measurements of acoustic intensity and impedance

Pascal

1996

The Journal of the Acoustical Society of America

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The pressure equalization vents of conventional microphones introduce bias errors in measurements of the sound intensity. Two error terms in the estimated active intensity are derived using a low-frequency model of microphone. The first error term is associated with the lower-limiting frequency of the microphones ͑1 to 2 Hz͒ and is proportional to the reactive sound intensity. It is shown here that the difference between limiting frequencies of the two microphones causes the second error term to be proportional to the mean-square pressure and to be of comparable importance at low frequencies. The amplitudes of errors due to the vents are analyzed in a quasistanding wave. Unlike the first error, the second can be corrected at the same time as the phase error between measurement channels, and several correction techniques are examined. For the error proportional to the reactive intensity, a correction method in a standing wave tube is suggested, using the joint measurement of several other energetic quantities. Examples of the influence of these errors on typical parameter values for half-inch microphones are presented in the case of measuring the acoustic impedance of materials using a two-microphone probe.

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Application of the sound intensity technique to measurement of field sound transmission loss

Cited by 11 publications

References 10 publications

Some Applications of the Sound Intensity Technique to Noise Control in the Workplace

Some Applications of the Sound Intensity Technique to Noise Control in the Workplace

Rancang Bangun Alat Ukur Koefisien Serapan Akustik (Halaman 26 s.d. 30)

The influence of microphone vents on measurements of acoustic intensity and impedance

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