linuxaudio.org

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On Thu, May 24, 2012 at 10:04 AM, Kevin Cosgrove wrote:
>

quoted text
> On 24 May 2012 at 13:52, Fons Adriaensen  wrote:

>

> > So that's at least three cases

> >

> > 1. Unwanted ambient noises

> > 2. Tape noise

> > 3. Vynil noise

>

> Other cases I've faced are:

>

> 4. Power line hum getting into the recording system.

> 5. Acoustic hum from florescent lights.

> 6. Noise from photocopier drum warming getting into

>   the power circuit with chirps every 12.6 seconds.

>

> I think Fons is onto something, find the cases for noise

> reduction, study the noise content, and devise or apply a

> suitable noise algorithm.

>

>

This is standard practice for anyone that does restoration work.  What Fons

has said, not to demean it at all, is common knowledge for those that use

the tools.  Your standard 4 tools are a broadband de-noiser, used for

relatively constant noises in the background, often a multiband expander at

least when dealing with realtime applications.  A De-Buzzer designed to

take at periodic noises that have relatively high harmonic content at

regular intervals, primarily a series of carefully designed notch filters.

A De-Hum which is designed to take out periodic noise without much harmonic

content.  And a De-Clicker designed to remove clicks and pops you get from

vinyl and other sources (ie. Dust on Tape going over the heads sometimes).

But also as he mentioned you can get more specialized tools as well and yes

some will go so far as to allow you to focus on specific spectral areas, if

anyone has seen Audition this does this, but really I am referring to much

more specialized tools that cost much more money, like Algorithmix

Renovator.

There is an 'ok' article on the basic process located on CEDAR Audio's

website, who are pretty much the standard in the industry to my knowledge

for realtime noise reduction(As compared to Algorithmix reNovate which is

offline/non-realtime)
http://www.cedaraudio.com/

Click on "About Audio Restoration"
At least it covers the basics pretty well if you click through to info on

the various tools at the bottom of the page.
        Seablade
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On Thu, May 24, 2012 at 10:04 AM, Kevin =

Cosgrove <kevinc@cosgroves.us> wrote:
On 24 May 2012 at 13:52, Fons Adriaensen <fons@linuxaudio.org> wrote:
> So that's at least three cases

quoted text
>

> 1. Unwanted ambient noises

> 2. Tape noise

> 3. Vynil noise

Other cases I've faced are:
4. Power line hum getting into the recording system.

5. Acoustic hum from florescent lights.

6. Noise from photocopier drum warming getting into

 =A0 the power circuit with chirps every 12.6 seconds.
I think Fons is onto something, find the cases for noise

reduction, study the noise content, and devise or apply a

suitable noise algorithm.

This is standard practice for anyone that does re=

storation work.=A0 What Fons has said, not to demean it at all, is common k=

nowledge for those that use the tools.=A0 Your standard 4 tools are a broad=

band de-noiser, used for relatively constant noises in the background, ofte=

n a multiband expander at least when dealing with realtime applications.=A0=

 A De-Buzzer designed to take at periodic noises that have relatively high =

harmonic content at regular intervals, primarily a series of carefully desi=

gned notch filters.=A0 A De-Hum which is designed to take out periodic nois=

e without much harmonic content.=A0 And a De-Clicker designed to remove cli=

cks and pops you get from vinyl and other sources (ie. Dust on Tape going o=

ver the heads sometimes).=A0 But also as he mentioned you can get more spec=

ialized tools as well and yes some will go so far as to allow you to focus =

on specific spectral areas, if anyone has seen Audition this does this, but=

 really I am referring to much more specialized tools that cost much more m=

oney, like Algorithmix Renovator.

There is an 'ok' article on the basic process located on CEDAR =

Audio's website, who are pretty much the standard in the industry to my=

 knowledge for realtime noise reduction(As compared to Algorithmix reNovate=

 which is offline/non-realtime)

http://www.cedaraudio.com/Click on "About Audio Restoration"At least it covers th=

e basics pretty well if you click through to info on the various tools at t=

he bottom of the page.

=A0=A0=A0=A0=A0=A0=A0 Seablade
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