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Re: Mic and system noise

Subject: Re: Mic and system noise
From: "Raimund" animalsounds
Date: Thu Feb 10, 2011 1:00 am ((PST))
> I may have cracked mic and system noise.
...
> I then sampled this hiss in Audacity 3.1 and used this as a noise
> sample using their noise subtraction command. With various recordings
> at the same level setting, Audacity took out the sample mic noise on
> all the recordings including a recording of hiss up to 20kHz.
>
> Comparing before and after in real time and also slowed down 10 times,
> I could hear no difference between the noise reduced version and the
> original except the absence of mic hiss. There were no audible
> artifacts or "gravel" effects.

David,

What you did here is a simple noise gate that removes or attenuates any sou=
nd components below a certain (frequency-dependent) threshold.

In theory, this mechanism will however introduce artifacts! Imagine you had=
 recorded a distant bird call that is partially buried in the system noise.=
 Then you will definitely get some kind of unpleasant distortion after appl=
ying this kind of noise gate filter...

> Next test will be with cheap =A39 mics to see if I could have saved two
> zeroes on mic costs. :-)

That would be too good to be true. But I'm afraid that you cannot bypass th=
e laws of physics ;-)

Regards,
Raimund













"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.



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