A numerical method for determining the radial wave motion correction in plane wave couplers

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedings – Annual report year: 2016Researchpeer-review

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Microphones are used for realising the unit of sound pressure level, the pascal (Pa). Electro-acoustic
reciprocity is the preferred method for the absolute determination of the sensitivity. This method can be
applied in different sound fields: uniform pressure, free field or diffuse field. Pressure calibration, carried out in plane wave couplers, is the most extended. Here plane wave propagation is assumed. While this
assumption is valid at low and mid frequencies, it fails at higher frequencies because the membrane of the
microphones is not moving uniformly, and there are viscous losses. An existing solution is an analytical
expression that estimates the difference between the ideal plane wave sound field and a more complex
lossless sound field created by a non-planar movement of the microphone’s membranes. Alternatively, a correction may be calculated numerically by introducing a full model of the microphone-coupler system in a Boundary Element formulation. In order to obtain a realistic representation of the sound field, viscous losses must be introduced in the model. This paper presents such a model, and the results of the simulations for different combinations of microphones and couplers. The results are compared to experimental data, and the existing analytical solution.
Original languageEnglish
Title of host publicationProceedings of Inter-noise 2016
EditorsWolfgang Kropp
Number of pages12
PublisherDeutsche Gesellschaft für Akustik
Publication date2016
ISBN (Electronic)978-3-939296-11-9
Publication statusPublished - 2016
Event45th International Congress and Exposition on Noise Control Engineering, INTER-NOISE 2016 - Hamburg, Germany
Duration: 21 Aug 201624 Aug 2016
Conference number: 45
http://www.internoise2016.org/

Conference

Conference45th International Congress and Exposition on Noise Control Engineering, INTER-NOISE 2016
Number45
CountryGermany
CityHamburg
Period21/08/201624/08/2016
Internet address

    Research areas

  • BEM, Metrology, Microphones

ID: 125697814