Subject: Re: [linux-audio-user] background hiss
From: Jason (hormonex_AT_yankthechain.com)
Date: Mon Feb 25 2002 - 11:39:36 EET
On Mon, 25 Feb 2002, Paul Winkler wrote:
> This won't work.
> Hiss is pretty much random; you'll never be able to cancel it with its
> opposite because you can't predict what its opposite will be at any
> instant.
Whoops! I see your point. thinking back about it, the times I've
succesfully used that technique have been with very specific noise like
air conditioners or refrigerators-don't ask- which had fairly regular
visible artifacts in the wave form that allowed for close synchronization
with the out of phase file. Looks like my confirmaion bias is hard at
work. That technique definitely does not warrant extraction to general
principle for noise reduction.
> There's a plugin somewhere called "dnoise" or something like that,
> it workd OK sometimes, but it does some damage to the signal.
> Removing hiss is really hard. You should always, always try
> to avoid it rather than correct it.
since i don't do much real audio work on linux(YET, I'm getting closer all
teh time) I tend to use sonic foundry's noise removal plugins to deal with
broadband constant noise like hiss. It works by taking a "noise print" of
an
isolated sample of the recorded noise then applying a frequency specific
volume envelope to the whole file based on a fourier analysis of the
components of the noise. I find it to be very effective most of the time,
is there any ladspa plug-in that works on a similar principle? Noise
reduction is a pain in the neck and always ends up in comprmise, but
sometimes there just is no way to get around it. Particularly if one is on
a budget and the part of teh signal chain is essential and too expensive
to be effectively replaced or dealt with physically.
-- YankTheChain.com - You can pretend we're not here. That's what I do.,
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