Abstract
For many decades, models that can explain the behaviour of measurement condenser microphones have
been proposed in the literature. These devices have an apparently simple working principle, a charged
capacitor whose charge varies when one of its electrodes, the diaphragm, moves as a result of sound
waves. However, measurement microphones must be manufactured very carefully due to their sensitivity
to small changes of their physical parameters. There are different elements in a microphone, the
diaphragm, the gap behind it, a back cavity, a vent for pressure equalization and an external medium. All
these subsystems form a strongly coupled device that cannot be modelled properly as a superposition of
submodels, but rather as a whole. For this reason, the challenge of microphone modelling is still an
ongoing area of research. In this work, a newly developed Boundary Element Method implementation
that includes visco-thermal losses is used to model measurement condenser microphones. The models
presented are fully coupled and include a FEM model of the diaphragm. The behaviour of the acoustic
variables in the gap and the effect of the pressure equalization vent are discussed, as well as the practical
difficulty due to the production variability among single units of the same microphone model.
Original language | English |
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Title of host publication | Proceedings of the Baltic-Nordic Acoustics Meeting 2012 |
Number of pages | 9 |
Publication date | 2012 |
Publication status | Published - 2012 |
Externally published | Yes |
Event | Joint Baltic-Nordic Acoustics Meeting 2012 - Odense, Denmark Duration: 18 Jun 2012 → 20 Jun 2012 |
Conference
Conference | Joint Baltic-Nordic Acoustics Meeting 2012 |
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Country/Territory | Denmark |
City | Odense |
Period | 18/06/2012 → 20/06/2012 |