Noise reduction in sections of a track

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kozikowski
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Re: Noise reduction in sections of a track

Post by kozikowski » Fri May 14, 2021 12:56 am

Post back if you get lost anywhere.

Koz

mwhelm
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Re: Noise reduction in sections of a track

Post by mwhelm » Sat May 15, 2021 7:13 am

I don't see an amplify->goal option, or an effect->hum remover
What version of audacity is this, or are these special plugins or?
Thanks, ==mwh

kozikowski
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Re: Noise reduction in sections of a track

Post by kozikowski » Sat May 15, 2021 8:55 am

amplify->goal option
Effect > Amplify as two windows. The top window is the gain or loss you want it to apply. The bottom window is where you want the work to end. The "goal."

You can force Amplify to put the peaks or tips to -1dB, just before clipping distortion. That's the bottom window. That's not a bad setting for generic works with no specific job.

If you run Amplify with all of the default settings, it will always try to push the work so the tips are at 0dB.

Hum Remover turns out to be a home-baked Nyquist tool you have to install. I'm going to find it any minute now.

Koz

kozikowski
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Re: Noise reduction in sections of a track

Post by kozikowski » Sat May 15, 2021 9:08 am

viewtopic.php?p=312438#p312438

Also.

de-hum.ny
(2.11 KiB) Downloaded 5 times

Audacity 3.0.2 has Tools > Nyquist Plugin Installer. After installation, you still have to Effect > Add/Remove Plugins to use it.

Koz

kozikowski
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Re: Noise reduction in sections of a track

Post by kozikowski » Sat May 15, 2021 9:33 am

Effect > Amplify is pretty handy. If you run it on some work, the bottom window defaults to 0dB (maximum volume) and the top window will tell you the boost needed to get it there. If you write down that number and add "-", that's the peak value of the work unless you change it.

Screen Shot 2021-05-15 at 2.25.30 AM.png
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The peak value of that sound is -16.021dB.

I think there's a limit. It will only boost or amplify 50dB before it gets tired.

But you can apply it more than once if you need to find the value of something really quiet. Add the numbers from each pass.

Also here.

https://manual.audacityteam.org/man/eff ... ml#amplify

Koz

kozikowski
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Re: Noise reduction in sections of a track

Post by kozikowski » Sat May 15, 2021 9:40 am

You said this way at the top of the message thread.

Audacity 3.02 on Windows 10

I hope not. The current Audacity is 3.0.2. Odd numbers can be somebody's custom version of Audacity and sometimes it's evil software.

https://www.audacityteam.org/

Koz

mwhelm
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Re: Noise reduction in sections of a track

Post by mwhelm » Sat May 15, 2021 4:34 pm

Audacity 3.02
That's a typo, sorry

mwhelm
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Re: Noise reduction in sections of a track

Post by mwhelm » Sat May 15, 2021 6:02 pm

Noise gate looks different than yours:
Screenshot 2021-05-15 100914.png
Screenshot 2021-05-15 100914.png (13.78 KiB) Viewed 105 times

mwhelm
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Re: Noise reduction in sections of a track

Post by mwhelm » Sat May 15, 2021 11:12 pm

This sequence of tools is very effective so far.

I have just found one horrible track where it made a bad situation worse; what I (so far) found most effective was to skip most of the tools, fool around with noise gate, & just suppress everything in the silent gaps like before. Maybe I'll post a small sample if you're interested, from the original. The whole sequence made the original poor quality audio unintelligible in spots. Which tool do you think has the most effect on voice quality? I didn't have time yet to try each one separately.

What I think is the most like what I was looking for is the noise gate. I'd like to understand this more. This seems to get rid of a LOT of unwanted noises including background in the talk &c without damaging the recording. I'd have to look for some musical tracks to see what happens there. But for tracks that aren't too bad it cleans up the whole thing w/o having to dip & dive. The other tools are useful but this one effects improvement I didn't have any approach to.

I have noticed that a few tracks still seem to benefit (to me) from more audio boost than this sequence provides. I am realizing I don't understand the amplify tool very well either.

Many thanks!

kozikowski
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Re: Noise reduction in sections of a track

Post by kozikowski » Sun May 16, 2021 5:19 pm

more audio boost than this sequence provides.
Taking this backwards. You are suffering from "The Software Should Know..."

The software doesn't know anything. All Amplify knows is that somewhere in your hour long presentation, one tiny bit of blue wave was higher than all the others and it latches on that as the reference for the whole show. If that one little wave happened to be noise, then it will push the desired voice into the mud to accommodate that wav. It has no idea what "noise" is.

There are certainly ways to set loudness, the audiobook people have that, but it tends to fall apart if you're in rescue or disaster mode.

The long, involved rescue I posted was intentionally designed so one single tool didn't dominate. You can set Noise Reduction for much higher corrections, See: Jademan, above, but then the voice will start sounding hollow, wine glassy, and talking-into-a-milk-jug. You may decide that Noise Gate is your go-to tool and it might be, but high gate settings can cause upcut first word sounds and/or word noise tails and used alone, it can leave high volume background noise between the words.

You can certainly have a tape so damaged that the tools stop working. That may be the tape you correct manually and that may be the tape you decide you can't fix manually, either.

Koz

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