about microphones and henns and eggs

[Martin Czech]

I always wonder, how the first measurement microphone was calibrated. You
know, for voltage you can use a bufferred chemical cell for good
accuracy. With that you can calibrate your voltmeter.

But a microphone?  The "very first" measurement microphone must have a
documented magnitude and phase plot, if you have that you can correlate
all measurments to that.

Kind of a henn and egg problem.

I guess there must be some clever standard sound source, be it impulse
or whatever.

Does anybody know about that?
Is there a "standard" sound element?


And further: If I'd be able to hire a pro measurement micro
for a day (Neutrik 3382, I learned that just a few minutes ago),
with individual data measurement sheet, I could correlate my cheap
electret capsule to it, even if it is a el cheapo unit.


That way, the cheap electret micro would be calibrated, I have
a know response. Would be usefull for absolute measurements...

m.c.