Audio Noise Filter problem

RichardB · Post by **RichardB** » Wed May 11, 2005 7:49 am

Does anyone have experience using the audio noise filter. I am working on a wedding project and the airconditioning fan is causing an irritating hiss in the background. It does not seem possible tot apply the audio filter in the video clip so I first made an audio file, added it to the music track and muted the sound of the video clip. When I apply the audio noise filter it either does nothing or mutes the sound completely. I used several settings under options from 3% to 10% with no success. Above 10% it mutes the sound completely. Am I doing something wrong or is the noise filter just a feature that does not work. The other filterss eg. Long Echo and Reverb appears to be working OK.
I am currently running UVS 9 but get the same result on UVS 8.

System
P4 2.8Ghz
1 GB Memory
2 x 120 GB Hard drives SATA
Win XP Prof. SP2

THoff · Post by **THoff** » Wed May 11, 2005 6:42 pm

I would recommend downloading the free Audacity Audio Editor, and using the noise removal tool it provides. Use UVS to create a separate WAV audio file, process that using Audacity, and load the clenaed up audio back into UVS -- simply mute the audio of the original video, or split the audio and video, and then delete the audio track.

RichardB · Post by **RichardB** » Thu May 12, 2005 10:51 am

Thanks THoff for the suggestion.
I downloaded and tried Audacity but did not get very good results. Probably because I don't know the product well enough. I also tried Nero Wave Editor which gave better results. It is however problematic to copy the sound out and edit it seperately as the whole sound file is displayed on one screen in Wave Editor. I have only tested a small section sofar to see if it works. To avoid Video/Audio sync problems I guess the only way to do it will be to work on the final rendered Video file. This however makes it difficult to select the sections where the filter is to be applied.

It would have been much easier if the UVS Noise filter actualy worked and could be applied to video clips without having to copy out the sound. To have a noise filter for the music track and the voice track seems rather pointless as you are in control of what you copy in there. When you are shooting the video you are not always in controll of the environment.

I hope someone from Ulead reads this and takes some action to fix and/or enhance the noise filter problem.

Thanks again

Post by **lancecarr** » Thu May 12, 2005 11:33 am

RichardB, I usually complete all my editing until I have a final product prior to outputting a video file. THEN I separate out the sound file and open with Nero Wave editor. Usually by that time you know the project inside out! First I find the section of the soundtrack I want to clean and then enlarge it so that it occupies the whole screen. I then carefully note the beginning and end if that piece. Then I find a section of the file that has the offending noise but with no other sound, like when the voices stop or whatever. I take a sample of that. Then I select the entire section I want cleaned, open the noise reduction dialogue and use that sample as key for noise reduction. I then test it and if ok save. I then put the whole file back into VS, mute all the clips in the timeline and I have NEVER had an OOS problem as long as I have been following the recommended procedure. Its kinda fiddly but very effective.

duffgnr · Post by **duffgnr** » Thu May 12, 2005 11:42 am

i also use nero wave editor but find the noise reduction has to be played with a bit!

too little makes no difference but too much has people sounding like robots underwater.

it is worth messing about with it though but i would rather see camera manufactuers devoting some attention to reducing motor noise etc.

duffgnr

RichardB · Post by **RichardB** » Thu May 12, 2005 12:31 pm

Thanks Lancecarr. If you say you seperate the sound file do you mean that you use the Split Audio function or do you create a sound file via the Share option. It is reassuring that I will not have OOS problems.
Thanks

Post by **lancecarr** » Thu May 12, 2005 1:01 pm

Sorry, that was a bit imprecise. Yes I go to "share" and then create a sound file. Then I save my project and close VS. I do that just in case any possible conflicts arise between the Ulead and the Nero teams on my computer! Then I open Nero and edit the sound file. The trick with Nero seems to be that you have to rummage around the file to get as "clean" a sample of the noise as you can and then only apply that sample to the area of the file it applies to.

RichardB · Post by **RichardB** » Thu May 12, 2005 1:08 pm

Thanks lancecarr. I did find a section of "pure" noise to sample and the result after filtering is very good. Thanks for your assistance
Regards
Richard

maddrummer3301 · Post by **maddrummer3301** » Thu May 12, 2005 3:37 pm

Hi,

If this is any help.

You need to use a notch filter.
You can define the frequency and swing above and below that center notch
frequency. Also adjust the attenuation/gain etc.
Then depending on the program your using you slide the notch filter along the
frequency band (changing it's target center frequency).
When you hear the noise disappear write down the settings your using.
Apply the notch filter to the file and export it.

Backup the original file first.
Also, you may have to apply the notch filter to more than one frequency.

Hope this helps,

MD