I completely agree with Dan.
The only noise reduction I consider acceptable is a smooth high pass filter
to remove rumble due to wind or distant cars/airplanes, or a smooth
low-pass to attenuate hiss above the higher notes I'm interested in.
Gianni
2012/2/10 Peter Shute <>
> **
>
>
> I'm experimenting with noise removal and some PCM M10 3 recordings in
> Audacity (beta 1.3)? now myself, as a stopgap solution till I can get som=
e
> stereo mics.
>
> My initial attempt, taking the noise sample from the recording, left the
> recording full of strange little hiccups and funny noises (but no hiss). =
I
> assume this was because I couldn't find anywhere where there wasn't at
> least one little bird calling faintly in the background.
>
> I then made a recording of just hiss at the same recording level with the
> recorder under some cushions, and I used that for the noise sample for th=
e
> noise removal. After experimenting with the noise removal settings, I
> started getting much better results, but still not right.
>
> At first I thought it was ok, but after listening a few times, I noticed
> that the reverb had gone, leaving it sounding very dead. I increased the
> attack/decay time and got some reverb back, but now there was a little
> burst of hiss each side of each loud bird call. More fiddling with the
> other settings, and I've improved it a lot, but the best way to improve i=
t
> seems to be to reduce the amount of hiss removed!
>
> I haven't given up yet, but given the amount of time I've spent on it now=
,
> and the imperfect results, I can see why people just shell out for better
> microphones. I assume that if I come up with some settings I think sound
> ok, people here will be able to point out other noise removal artefacts I
> hadn't noticed.
>
> That said, at this stage I still think it's worth a try if all you have i=
s
> the recorder's internal mics. I hadn't noticed the hiss at all in other
> recordings I made in noisier places, so it's only in very quiet places th=
at
> it's a problem.
>
> Peter Shute
>
> ________________________________
> From: [mailto:
> On Behalf Of Dan Dugan
> Sent: Friday, 10 February 2012 10:16 AM
> To:
> Subject: Re: [Nature Recordists] Sony PCM-M10 vs Zoom H4n best for
> outdoors / capturing frogs in the jungle?
>
> > One thing that seems important to master for now, esp when using the
> built-in mics, is removing microphone hiss with Audacity. Do you recommen=
d
> this method?:
>
> No. Noise-removing algorithms damage the sound irreparably. There are of
> use in forensics, and in constructing mixes for film, where destroying th=
e
> ambience of a particular clip doesn't matter because another ambience is
> being mixed in.
>
> The way to avoid hiss is to get the mics closer to the source, or use
> quieter mics.
>
> -Dan
>
>
>
>
--
Centro Interdisciplinare di Bioacustica e Ricerche Ambientali
Universit=E0 degli Studi di Pavia
Via Taramelli 24, 27100 Pavia
http://www.unipv.it/cibra
http://mammiferimarini.unipv.it
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