Re: [LAU] Realtime sound level measurement with logging

From: Michael Jarosch <riotsound@email-addr-hidden>
Date: Sat May 13 2017 - 00:56:31 EEST

Am Freitag, den 12.05.2017, 10:47 +0100 schrieb Jonathan Gazeley:
> Is there a decent application that can monitor 
> and log data in this way?

What you describe is pretty much the same stuff I was teached last
weekend...

I don't know what (linux-)program fits best for this task, but I would
also appreciate a hint for doing a DIN-15905-5-compliant measurement on
linux. :)

> I'm also open to the idea of just recording a WAV file over 24 hours
> and 
> doing the analysis afterwards, with periodic readings from the file.

I know a tool called "replaygain". It's used to compute the loudness of
a soundfile. But, actually, this is another task and - as much as I
know - has nothing to do with determine a sound pressure level...

What you need is something that determines an average value of the
sound pressure you're recording in dbFS. Then, you "only" have to know,
what sound pressure level represents 0 dbFS. But if you're talking
about perception, you also need some kind of weighting... Not that
easy...

> Is my approach reasonable, to set up a microphone and use the gain
> knob 
> to calibrate it against the handheld meter?

Could work, if you find a program that works exactly like that handheld
meter. That means: Same weighting, same time periods. There are
standardized weighting and time periods (slow = 1s, fast = 125 ms), so
chance is you could be lucky.

> I don't need amazing accuracy.

You won't get much accuracy, anyway, as long as you don't use "class
1"-equipment which costs several thousand euros.
Even with "class 2"- equipment, 3dB is nothing. At least, this is what
my tutor said last weekend.

Greets!
Mitsch
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Received on Sat May 13 04:15:01 2017

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