Soundforge and Hiss

[Fozzee]

Hi

I have this movie with hiss and would like to apply a process to it and clean up the sound.
I have little experience with audio software.

Please Help.

Fozzee

[secretagent]

sound forge is limited in its ability to clean up hiss. they want you to buy there noise reduction plugins, that said you can either use the nosie gate or the equaliser functions located under th effects menu. it allows you to preview the results and comes with presets. just choose a preset and listen to see if you like the results. a better program is wavclean (freeware) designed to do this but the most superior method i have found is with cool edit which has built it hiss removal and noise reduction where you sample the noise then cool edit removes it (almost perfectly from the source)

[Fozzee]

Hi
Any chance of a quick guide on how to do that as I've never used Cool Edit b4.

Cheers

Fozzee

[gadgetguy]

Hope this helps...

To remove hiss from audio in Cool Edit…
1. Extract the audio to a .wav file
2. Start Cool Edit and open your .wav file.
3. Locate a portion of the audio that would be silent if not for the hiss.
4. Select a very small portion. The smaller the sample the better, because there is less chance of removing audio you want to keep. You can be very detailed in the selection by directly entering the Selected Start and End fields down in the lower right corner.
5. On the menu Click Transform, then select Noise Reduction
6. On the Noise Reduction window click “Get Profile From Selection”. If it is disabled you will need to increase the size of the sample. You have to find that balance of having the sample small enough to only get the noise you want to remove, but big enough that a filter can be created. Then click Close. (You do not need to save the profile, but can if you want).
7. Select the entire audio, or the portion that you want to remove the hiss from.
8. Again click Transform, then Noise Reduction.
9. The noise reduction window will open with the profile created the first time.
10. Make sure the radio button is selected for “Remove Noise”
11. Click OK and the hiss will be removed.
12. Then save the audio file. (I like to Save As under a different name and keep the original file intact until I finish the project)
13. Remux your audio and video.

[EddyH]

a couple of "little" things i would add onto that otherwise sterling instruction...


First up, under win98 at least with the cool96 shareware, cooledit seems to run foul of some 2gb (?i dunno) maximum filesize bug, which includes the undo buffer, temporary workspace, and some slack/scratchspace so the largest "safe" single file that you can work on at a time is ~500-600mb before risking overflow and corruption. The program doesn't warn of it, it just happens - bitter experience has shown the first sign of this is when you play the file and near the end (or sometimes, the start!) sections start repeating, faster and faster, till its a big garbled mess because of the overflowed bits.

(winme, 2000, xp may not exhibit this, nor the newer versions of cooledit or their demos.. just assuming that you may be running an older windoze, and have got hold of the time-unlimited older demo...)

The workaround is fairly easy and doesn't cause any noticable change to your audio, though. You can work on small portions of large files, and cut and edit, without much problem, so long as you don't run whole-file filters. It just requires extra time, extra steps, and some extra disc space.
Load up the big wav. Work out how many pieces you'll need to cut it into, to make safe sized sub wavs (eg the average 2-hour film splits into 3... no more than about 45 minutes for each 48khz subfile, or 50m for 44khz). Select roughly that amount (doesnt have to be exact) of the start of the wav. Press F4 so that it crops to where the wave trace is at zero (makes for cleaner cutting). Hit zoom, then view - viewing range, and put the start back to zero if it already wasnt. If you changed the viewing range, deselect the wave portion and double click on the trace to select the whole visible part. Then do file - save selection as... and choose a sensible name (eg terminator 2 soundtrack part 1). Wait for it to save. Press delete to remove that section from the big wav. Rinse and repeat for the other parts.

Then open up each subwav to perform the actions you otherwise would have done on the whole big wav without the risk of corruption... save them all normally, and when it's all finished, open part one... then open append parts two, then three, four... for some reason open append always takes forever so be patient. The result of this is how your big wav would otherwise have looked, and is save to save as the rejoined full soundtrack ready for encoding/etc.
Remember to amplify each subwav equally if you increase the volume. Normalisation will require testing each one for loudest volume and raising each of them by however much is required for the loudest one to be normalised...



Noise reduction.
The best way for accurate noise reduction is to end up with 10 seconds or more of continuous noise (and for some movies its a minute or two). Open a second copy of cooledit. Roll quickly through the file using the spectral trace, and -ears- when unsure, to identify parts where there's nothing but hiss and hum. Copy these out (using the f4 key again so they all join up well later) and paste sequentially into the second copy. Take many samples across the whole soundtrack.
When finished, if you play the collected samples in the second copy, it should sound fairly continuous and even. If it gradually changes over time, then that's OK - one of the good things about this method is that it compensates for that, rather than the different noise coming and/or going. However if there are certain points that are distinctly louder or abruptly have a different sound that wasnt immediately obvious when sampling, cut them out. This way you get a nice big sample to take a high-stat-number reading from in the noise window, and dont accidentally take any real sounds.
The noise samples can be saved like any other wav, if you think it may be a neccessary backup, as can the noise profile. In this case it's required. Take the sample (between 50 - 500 stat samples is good, depending how long your noise collection is; an FFT of about 2048 is usually fine) and save profile as -yournamehere.fft-
The second window can now be shut.... go back to the actual soundtrack wav/s, open noise reduction, load the freshly made profile, maybe do some tests on a small, conspicuous area as to how strong and tweaked it needs to be (strength of 80, precision 17, smoothing 1 and transition width 4db is another good all rounder, but some situations require different stuff - plus, 17 is slow , then select the whole wav, set it filtering, and go have a shower... a coffee... walk the dog... etc. Highly dependent on CPU speed! 600mhz = just-about real time.

Then give it a listen, you like what you hear, then save it and go on to the next stages. If not, undo or revert and tweak again...




(yes, this method calls for a very -large- sample, but the trick is that it's not a contiguous one and smooths out any undetected mistakes or signal noise too. the pick-a-small-one method still works if you dont have much 'virgin' noise, or a short piece like a music video with a halfsec of silence at each end...)

[txpharoah]

sound forge is limited in its ability to clean up hiss. they want you to buy there noise reduction plugins, that said you can either use the nosie gate or the equaliser functions located under th effects menu. it allows you to preview the results and comes with presets. just choose a preset and listen to see if you like the results. a better program is wavclean (freeware) designed to do this but the most superior method i have found is with cool edit which has built it hiss removal and noise reduction where you sample the noise then cool edit removes it (almost perfectly from the source)

Absolutely not. You just have to know what you're doing.

DartPro 98 is a pure restoration program. But SoundForge has some great filters. You can even customize them.

The guide in my signature has some information on sound restoration.

Under the PARAGRAHIC EQ, you can apply the default HISS CUT filter. Just tweak the low shelf to 5,000 or lower if you need more hiss cut out. You can even preview the changes.

CoolEdit is good, but does not come close to the abilities of SoundForge or DartPro 98/XP in terms of restorations.