I need help with Noise Reduction Please! Like ASAP! Thanks!

[Ramroumtx]

Hello,

I have a small audio clip in here that I got the noise profile and did the the noise reduction for. I was wondering why I can't get rid of that noise is the background? Its like it creates this weird mechanical noise whenever I do the noise profile. I will upload a small click so someone can hear what I'm talking about. Please help asap! Thanks!

MBP: 10.11.2
Aud: 2.1.1

[steve]

Noise reduction is always a trade-off between how much noise is removed and how much damage is caused to the remaining audio. The art is in getting the balance between these two conflicting measures. If you attempt to remove ALL of the noise, then it will almost certainly cause noticeable damage (of the kind that you can hear in that MP3 clip).

If you could post a short sample (just a few seconds) in WAV format of the unprocessed audio, then we will be able to suggest some settings.
Please ensure that the sample is in WAV format, is unprocessed, and includes both some talking and some "noise only".

[Ramroumtx]

Took me forever to get that lower than 2mb in here! I hope this helps. Its unprocessed and in WAV.

[kozikowski]

That's about the best I can do. You're never going to achieve a theatrically presentable monolog out of that. The volume levels are terrible and it's all noise.

Effect > Equalization > Steve's custom rumble filter. I'll tell you how to get that if you decide to do this.

Run Noise Reduction with 7 seconds to 7-3/4 seconds as the Profile. Correction values 12, 6, 6. Do it again with the same location for the profile. This time correct to 6, 6, 6.

Reduce the show to mono. Tracks > Stereo Track To Mono.

Koz

[steve]

As koz implied, you can't make a great recording from a poor recording. The best we can hope to do make it less bad.

This is what a raw unprocessed stereo voice recording should look like:

firsttrack000.png (11.89 KiB) Viewed 610 times

In contrast, this is what the sample looks like:

firsttrack001.png (8.94 KiB) Viewed 610 times

It's clear to see that in the first example, the voice level is much higher than the noise level, but in the second picture the noise is almost as loud as the voice. With so much noise and so little voice, the best that we can hope to do is to reduce the noise a bit and try not to damage the voice too much. I doubt that it is possible to get it much better than koz's example even if you spend a lot of time on it. The only way to get the recording substantially better is to re-record and get the voice level higher.

[Ramroumtx]

The problem is these are coming from old cassettes or records or audio reels. Thats why they sound like that so I can't really re-record them. What is Steve's rumble thingy?

[Ramroumtx]

OK so I went ahead and did it but I am a little confused...I thought when we go to do the "Get Profile" that the areas selected should have no audio. Just noise? Am I right? So thats what I did. But then you told me to do the same thing again after I apply? But how can I "Get Profile" again when I have to select it to the entire audio clip?

OK so this is what I did:
1. Selected a 20 second area at the end with just noise
2. Get Profile
3. Then selected the entire clip and entered 12/6/6 and ran it.
4. Note: I did not do "Get Profile" again in this step...If a I am supposed to, what area am I supposed to select since I ran it already?
5. Then I selected the entire clip again and entered 6/6/6 and ran it.

Are those the right steps?

[Ramroumtx]

Ok. After we finish with the previous audio...I attached another audio project that I need help with...This came off a 78 LP Record. How can I clear this up?

[kozikowski]

Drag-select the exact same profile area you did the first time. The object is to run the whole Noise Reduction process the second time to work on any noise the first pass might have left behind.

http://www.kozco.com/tech/audacity/Docu ... ch.xml.zip

Unzip the file to LF_rolloff_for_speech.xml

Adding Audacity Equalization Curves
-- Select something on the timeline.
-- Effect > Equalization > Save/Manage Curves > Import
-- Select LF_rolloff_for_speech.xml > OK. (it won't open the ZIP. You have to decompress it)
-- LF rolloff for speech now appears in the equalization preset curve list.

You have to increase the panel Length value to maximum (8191) to use this filter.

Koz

[Ramroumtx]

Ok got it thanks! Now how do I get the other one cleaned up?