We use microphones to monitor the acoustic noise level in the PSL and right above the AS port table.

We also want to use these microphones to remove noise via the active noise cancellation.

[[http://en.wikipedia.org/wiki/Microphone|Wikipedia-Mics]]

Josh's stream of mic thoughts: [[PEM]]

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==== Robert Schofield's Thoughts ====
''Hi Rana, ''

''I meant to say electret condenser microphone. There is nothing inherently wrong with these, its just that there is a cheap design that has an on-board preamp with AGC that is very common. Its quite popular specifically because of the AGC. ''

''I think that a good condenser mic is the best way to go since they sense pressure directly rather than pressure gradient (like most dynamic microphones). I think that most calibrated microphones are condensers like our B&K. ''

''If you get a consumer condenser, make sure that the "bias" is not actually a pre-amp supply. ''

''Robert ''

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=== Microphone Spectra from LHO ===
Its in Pa/rHz. The ISCT4 MIC is in an acoustic enclosure so that gives you a good idea of the noise floor. Not sure if this is a microphone noise floor or a ADC noise floor.
LHO Uses the B&K something something microphone.
{{attachment:LHOmics.png}}

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== Useful Links ==
[[http://www.epanorama.net/circuits/microphone_powering.html|How to power microphones]]