Noise reduction

[OB1K]

Hi everybody,

I have a sound related problem but it is not an encoding problem.

In fact, I got an avi file where the sound is very low.

So, I extract it and normalize it. But the result is not very good because I also amplify the noise by a factor of 5.

So I try to apply a noise reduction filter with GoldWave but few noises remain and the voices are a little different.

As I am not a specialist of sound treatment, I don't know how to do and where to adress my problem.

So, If someone has an idea, he woould be nice to give me (sorry, but with some details, because I am newbies with sound).

Bye and thanks for your responses.
OB1K

[tangent]

Originally posted by OB1K
So, I extract it and normalize it. But the result is not very good because I also amplify the noise by a factor of 5.
What codec is the audio stream encoded in?
If the audio in the avi is in MP3 format, you can use mp3gain to maximize the volume optimally. http://www.geocities.com/mp3gain

[OB1K]

What does MP3Gain do exactly? It normalize the sound but don't treat it for a noise reduction. Do I make a mistake?

[MaTTeR]

You can also look into the DeDynamic filter which does an excellent job in increasing volume while watching the movie. PowerDivx has built-in support. Try it and I think you will like:)

[OB1K]

I think that I don't explain very well.

My source is already with a buzz but as it is very low, we can't hear it. When normalize, voices are very good but the buzz is also amplify and then become very disturbing.

So, I want to treat a source which is already with a buzz. It is not the normalisation that causes buzz.

So, I think that I have to use a sound filter on few frequency but I don't know which frequency and which filter... Noise reduction of Goldwave transforms voices but I think I don't put the right parameters.

Help!!!!!!! I don't know what I can try.

Bye.
OB1K

[MaTTeR]

Sorry I misunderstood what you were after.

CoolEdit has alot of filters to clean up sound artifatcs such as a buzz, pop or hmm. I don't know the name of a filter off the top of my head for CE or GoldWave though. I'd think you could do a quick search with your favorite search engine and find a few filters to try out.

[OB1K]

OK, thanks, I will try as soon as I got Cooledit.

OB1K

[movmasty]

i use Soundforge to remove buzz

you can do that in 2 steps

1) remove it with the noise reduction plugin

2)dont use a simple normalization, but the dinamic one
that means to not apply the gaign at the noise level

[philippas]

I have a very noisy vcd which i wanted to remove the noise from the audio stream. I used virtualdub to decode the audio to wav and coolEdit 2000 to apply noise reduction.

My problem is that if i remove a lot noise of the audio the audio becomes metallic(it sounds like a compressed stream @ 20kbits.)
I can't seem to find the sweet spot that a lot of noise is gone and not alot of metallization is introduced.

Is there an option or a filter to remove the metallic artefacts after the noise reduction?

[LigH]

From my experience, the noise reduction in CoolEdit is quite well working, but not the ultimate "magic wand": It changes the frequency distribution relative to the detected noise floor, therefore it may introduce artifacts, depending on a) how good the noise floor is measured, and b) how strong the noise reduction is applied.

In my experience, the only way to reduce these metallic artifacts is to reduce the noise reduction strength, hence leaving a bit more noise in the final audio.

It is indeed possible that better noise removal applications exist, but I don't know about the quality of such programs; in general I would guess that all tools working with the same technology will create similar results.

[philippas]

what values do you suggest for the noise reduction settings ?

[LigH]

Sorry, I can't recommend any settings. All I can recommend is to try it with a rather short snippet and with many different settings between e.g. 30% and 70%; 100% noise reduction is usually too much. (Is there a preview?)

"Versuch macht kluch..." - try and get experience.

[philippas]

Yes i know i have to try different % values for a given source.
But is it worth playing with the precision value or just leave at default 8 ?(if you increase alot the process becomes very slow).
Also how about the FFT points ?

[LigH]

In my humble opinion, a very high precision or a very fine FFT resolution is only useful for rather non-uniform noise, so for the case that specific frequencies are appearing more or less often. I would guess that a too high precision may create stronger metallic artifacts; but don't count on me here!

[philippas]

OK Thanks :)

[komaklar]

heho!

yesterday i have downloaded bridget jones 1cd rip!
the video looks good, but the audio has some strange noise (something like a waterfall) in the background...
i tried cool edit nosie reduction and the quick filter options without satisfaction.
if there is any other prog to filter out these noise, please let me know.

tschü
komaklar

[ivan_alias]

The best thing to do is buy the DVD and do a fresh rip. That way you can ensure that you have the best quality audio.

[komaklar]

thx ivan for your inovative help, but i have found a solution useing the nero wave editor --> noise reduction!
just for the archives ...


:) komaklar

[markrb]

I have downlaoded a couple of movies and in both cases there is a constant buzz throughout the entire movie. Is there anyway to specify the buzz in something and squash it without destroying the entire audio? Maybe find the specific frequency and remove it?
Probably not, but I had to ask.

Thanks,
Mark

[MaTTeR]

Though I've never tried it before you could use something like Sonic Foundry Noise reduction, Dart Pro 98 and perhaps even CoolEdit has some noise reduction plug-ins.

I'm curious also, so if anyone has experience in the subject...

[tenebrenz]

Cooledit Pro would be a wise choice for this type of problem. I would try to remove about 75% of it with the notch filter at 50 or 60hz (if the source is AC hum) and the rest with the noise reduction tool. All you do is find an area which contains only the noise you want to remove and use that as a profile to remove that particular sound from the entire file.

[markrb]

I downloaded Cooledit Pro and played with it for a bit. Didn't have as much time as I wanted, but Poker called.:D

I am a complete newbie to this so bear with me please. I tried the notch filter at both 60hz and 50hz, for both types of power frequencies since I have no idea where it was made. Neither had any effect. I tried the frequency analyzer and put my mouse over the silence(except for the buzz) at the beginning and it said 43Hz so I set the notch filter on 43 and still it had no effect.
I then tried the noise reduction section and the buzz went away, but the audio changed pitch and sounded like it was in a tunnel. I did it again with much lower numbers then the default and it does sound better, but it still changes the audio a bit, but not nearly as much as before.
If I make a small wav sample of say 30 seconds could someone take a quick look and maybe see if they can do better with basic tools and techniques that they could pass on? If I can get this to work I maybe able to do the same thing on a movie I got, but tossed out since the audio was filled with the same buzz. It's the one with Frodo and all his buddy's.

Thanks,
Mark

[Mental]

I've had som good results with DartPro in these cases. Just find a part of the movie where you only hear the buzz/hum and make a noise-print, that the program will use to filter out the noise.

[markrb]

Thanks for the replies I tried everything mentioned here and nothing makes a difference. I was really surpised that with DartPro and noise print there was no difference at all. I would have thought if I gave it a sample it would eliminate that sound, but I guess it doesn't work that way. I tried hum removal in both programs with no luck either. I guess I am out of options.

Thanks,
Mark

[PeterTheMaster]

the one with frodo and his buddies? could it be it was recorded with a video camera in a cinema?
maybe this would held identifying the source of the noise.

[markrb]

Actually they are Tele Sync. It's not quite a video camera on a tripod, but it's not far off.

Mark

[PeterTheMaster]

what is "tele sync"?

[markrb]

It's a way they run a projector directly into a video camera instead of on a screen and have the camera go on the screen. The audio is plugged directly from the projector into the video camera. It's a step above a regular camera capture. No audience noise or walking in front of the camera. I don't know much more then that. I have never seen the equipment they use. They have to have access to the reels. Usually a projector operator of a cinema is in on it.

Mark

[bjfacca]

I was getting this annoying noise in my video captures (PV-BT878P+) so today I decided to hook up my TV audio out to my PC's in and record the audio from the TV. Guess what? The same noise!

After trying a lot to isolate the noise I finally did it, with the TV plugged to the computer I set the voulme (in the TV out) to zero and tried to record in the PC, I only got this noise (please listen to 76kb mp3 here http://planeta.terra.com.br/lazer/bjfacca/noise.mp3), when I disconnect the cable from the TV out and try to record I get no noise.

The really strange thing is: I only get this noise when I'm listening to a record, when I'm listening in real time the sound is totally clear (I already tried every compression and frequency possible). :confused:

The only things I could think of are:
1 - Bad grounding
2 - Some kind of interference from the cable TV's cable (you know what I mean), I was getting some weird horizontal waves in my monitor every time I hooked the cable to my pc.

Forgot to mention that the noise in the attachment is amplified to 300% to make it easier to hear

Any ideas will do

Thank you
Bruno

[bjfacca]

Please, anything. :(

[makaone]

I have just recorded a wave file from a tape deck and want to put it on cd.

I'm just wondering if there is a prog that can remove the annoying static in the back ground.
Have tried to "dolby NR" to no avail. It does work but not enough.

If it can't be done so be it , but it would be good to beable to do to clean up sound tracks.

Any help greatly Appreciated.

:confused: :confused:

[DJ Bobo]

You can do it in CoolEdit.
Select at least one second of silence. Go to the Noise Reduction menu, click "Get profile from Selection", Set noise reduction level to something like 75, click "Close", select the whole WAV, go back to the Noise Reduction menu und click "OK".

[pacohaas]

if you don't want to pay for CoolEdit, BeSweet has some nifty plugins that would probably help, such as noise gate.

[DSPguru]

http://www.dartpro.com/

[yawnmoth]

Sony has some noise cancelling headphones, you can read about here:

http://www.sonystyle.com/is-bin/INTERSHOP.enfinity/eCS/Store/en/-/USD/SY_DisplayProductInformation-Start;sid=lbAY4Dq_1lMYwwdhW34S63WzWsWcpWFawKU=?CatalogCategoryID=6qUKC0%2eNwIcAAADxoGUXu6tK&ProductID=%2e6AKC0%2eNIsMAAADxZ5kXu6tM&Dept=pa

Anyways, it requires batteries, and from what I've read, it seems like it has a microphone that picks up noise, and cancels them out through the headphones. So... is there software to do this same thing, if you have a microphone and speakers, or something?

[rjamorim]

By "noise cancelling", do they mean dehissing/decrackling/etc?

Because, if that's the case, you can do it with DirectX plugins.

The best ones come from Waves: www.waves.com

Regards;

Roberto.

[yawnmoth]

i don't think that's what it means...
from the description:
The Noise Canceling circuit actually senses outside noise with built-in microphones and sends an equal-but-opposite canceling signal to the headphones.

[echooff]

I have been looking for a while and haven't found the answer in the guides or Any thread posted for the last year. I have a home video of a family reunion. In the background there is a loud noise of either a lawn edger or chainsaw. How can I either remove the noise or dampen it to a much lower volumn. Any sugestions are appreciated. If I need to buy a audio package to solve it, I will. Please help.

[cweb]

I remove hissing noise present in my video captures using these Cooledit settings:

Noise Reduction Level 72
FFT Size 12000 points
Number of Statistical snapshots in profile 85
Remove Noise
Precision Factor 7
Smoothing Amount 1
Transition Width 1

I don't know if it will work for anything else but hissing.. you have to try and see..

[numlock]

I need help cleaning my audio recording, it has a lot of background clicking, poping, etc. like a very old LP

Here is a short sample audio file:

http://video.wtlzone.com/noisy.wma (37 kB)

TIA

[JuanC]

If you own nero burning rom, you also got Nero Wave Editor, which is a great app. for that. You can take a look at the options in the menu under "Enhancement". Also CoolEdit Pro is a professional level application which include lots of tools.

[SallyDog]

Try this. Lots of good info and software links.

http://www.delback.co.uk/lp-cdr.htm