Subject:background noise reduction

Posted by: Jim_Rogers

Date:8/21/2013 6:34:33 AM

I'm trying to edit some recorded sound tracks. These were done outside and there is a lot of background noise from a nearby highway. I want to remove this background noise.
I'm using sony Sound Forge Audio Studio 10.0 build 245.
Can anyone point me to a thread where this solution is posted?
Or can anyone point me to a filter, process, or option in the program that will "read" this background noise, and the suppress it on my tracks?
Any help or suggestions will be helpful. Thanks.

I did a search here for this solution and there was a thread about "road noise" but the solution given there was to use a better microphone. I have a good mic but I need to understand how to use this program to suppress the unwanted back ground noise.
I have tied noise gate, but it doesn't get all of it. And when I turn it up to get all of it I loose some of the sounds I want.

Thanks in advance again.
Jim

Subject:RE: background noise reduction

Reply by: Steve Grisetti

Date:8/21/2013 7:32:36 AM

It's very difficult to remove wind, traffic and other background sound from audio. In fact, even Hollywood pros often have to re-record (or "loop") dialog in a studio to replace the dialog in a scene shot on a noisy or windy day.

If you've got sound of a particular frequency (say cicadas or an electronic hum) you can sometimes filter out the sound without making the rest of the audio sound unnatural. But you can't do miracles. You can't somehow separate the wanted audio from the unwanted.

A highly directional microphone with a good windscreen can help. There's really no substitute for getting it recorded right in the first place.

Subject:RE: background noise reduction

Reply by: roblesinge

Date:8/21/2013 7:37:57 AM

First off, know that you probably won't be able to remove all of the noise. In fact, you may do more damage to your recording than good, just because traffic noise is not static, nor is it confined to one part of the spectrum. So, anything you do should be in small steps so you can monitor each change and its negative effects on the good parts of your recording.

That being said, is this recording of just dialog or is there music? If it's just voice, the first thing I would do is run an EQ highpass filter at about 120Hz to kill rumble. Then I would try and find a small example of the noise you want to remove, only a few milliseconds is necessary (note this works best if the noise is static and mostly constant). Then launch the Sony Noise Reduction plug-in. Capture a noiseprint of the section you just found and then run a reduction on the whole file or the portion of the file you want to work on. I would do this in no more than three steps of no more than 12dB of reduction each, getting a new noise print each time. Using a noise gate will only get rid of the noise in the silent parts of your recording. I recommend only using that as a last step.

Beyond that, mitigating this during recording is the only way to solve this problem completely. Noise reduction works for some situations, but the one you're describing typically isn't one of them. I wouldn't say you need a better mic, I'd say you need better mic technique.

Good luck,
Rob.

Subject:RE: background noise reduction

Reply by: Doug_Marshall

Date:8/21/2013 9:30:14 PM

Jim, Depending on how important rescuing the recording is to you, SpectraLayers from Sony might be helpful. It's a surgical program that helps you isolate unwanted noises by making their sound patterns visible by frequency. Some extractions are miraculously easy while others take great effort. Patience is a virtue and there's definitely a learning curve but I've removed or reduced clunks, bangs, hinge squeaks, quiet conversation, and footsteps from soft, continuous pipe organ music without any disruption to the sound of the pipe organ. SpectraLayers has become a very worthwhile new tool in my repair arsenal but it can take you a lot of time to go after each of the sounds that make up the problem.

Subject:RE: background noise reduction

Reply by: Iacobus

Date:8/22/2013 11:41:09 AM

Second what Doug said about SpectraLayers; very nice application if you're wiling to learn its UI. (To be honest, it wasn't that hard to get down the basics and I'm a lowly musician.)