View Full Version : background noise
Stephen Sobel December 29th, 2008, 06:59 PM I did some videotaping on a recent vacation (with my Canon XH-A1). I have one segment where I was videotaping a group of people sitting on an outdoor stage several hundred feet away, with a crowd of people sitting (mostly) between the stage and me. The mic picked up the sound from the loudspeakers, but it also picked up a low murmur of chatter from some of the people around me. Is there any way to filter out the chatter using Vegas Pro 8?
Daniel Browning December 29th, 2008, 07:19 PM The short version is "no".
The long version is: "pick two".
Experience
Time
Money
If you have Experience and Time, you can use simple EQ (dozens or hundreds of passes) to isolate and filter out the unwanted sound.
If you have Experience and Money, you can do the same with expensive noise reduction software.
If you have Time and Money, you can trade them for Experience.
Sometimes the nature of the noise is such that it just can't be isolated from desired sound, no matter your resources.
Stephen Sobel December 29th, 2008, 09:27 PM The short version is "no".
The long version is: "pick two".
Experience
Time
Money
If you have Experience and Time, you can use simple EQ (dozens or hundreds of passes) to isolate and filter out the unwanted sound.
If you have Experience and Money, you can do the same with expensive noise reduction software.
If you have Time and Money, you can trade them for Experience.
Sometimes the nature of the noise is such that it just can't be isolated from desired sound, no matter your resources.
I haven't used EQ before, though this may be a good time to learn it. I'm using this videotape as a learning tool for myself. Is there a tutorial somewhere that could get me started on trying to learn EQ?
Daniel Browning December 29th, 2008, 10:21 PM I haven't used EQ before, though this may be a good time to learn it. I'm using this videotape as a learning tool for myself. Is there a tutorial somewhere that could get me started on trying to learn EQ?
I don't know. I haven't really learned it myself, I've just used a few (relatively) inexpensive programs: SoundSoap and the Sony Noise Reduction plugin. I'm sure there must be some good information somewhere on the web, but who knows. I'm even more certain that there are great books on the subject.
In any case, I think it would be wise to start the learning curve with something that's much easier to remove. Generally, the more different the noise is from the signal, the easier it is to remove. Hums, hisses, motor noises, etc. will be easier to remove (I would guess) than people talking.
I didn't see any threads with that kind of information when I searched dvinfo, just high level discussion:
http://www.dvinfo.net/conf/all-things-audio/103758-how-can-i-cleanup-background-noise.html
http://www.dvinfo.net/conf/all-things-audio/91508-filtering-out-motor-noise.html
Good luck!
Jason Robinson December 30th, 2008, 02:43 AM I haven't used EQ before, though this may be a good time to learn it. I'm using this videotape as a learning tool for myself. Is there a tutorial somewhere that could get me started on trying to learn EQ?
I found that the VASST training disc #5 dealing with Audio Correction to be very helpful, however, the training makes heavy use of the Soundforge plugin "Sony Noise Reduction" which is absolutely worth the $300.
The training DVD disc #5 has been pulled from the VASST site, though I don't know why (possibly because it used a lot of commercial plugins that someone that only owned Vegas would not have access to).
Another training resource that is totally worth it is disc #4 which is color correction in Vegas. Discs 1-3 won't teach you anything if you have used vegas for more than a few months.
Ian Stark December 30th, 2008, 04:13 AM Personally I think you're on a hiding to nothing here Stephen, sorry.
I'm not convinced that EQing is going to allow you to filter out unwanted voices while retaining the ones you want, no matter how much time or experience you have. Even the expensive noise reduction software would struggle with that.
Having said that, take a look at iZotope RX - that may go some way to achieving what you want (at a price, though). RX contains a tool called Spectral Repair which helps to clean up intermittent noises - whether that will work on background chatter I am not sure.
To my knowledge, the other noise reduction tools are aimed at broadband noise and hum rather than intermittent noises, but I'm happy to be corrected.
You could try asking the question at the All Things Audio forum - that's where the sonic experts hang out.
Stephen Sobel December 30th, 2008, 04:17 PM Thanks, all!
John Cline December 30th, 2008, 11:19 PM I've been involved in forensic audio for quite a while and what you're attemting to do is essentially impossible, particularly if you have any hope of having the audio sound the least bit natural after processing. It's my opinion that you just need to live with the audio as it exists and don't waste any time trying to fix it.
Stephen Sobel December 31st, 2008, 06:15 AM I've been involved in forensic audio for quite a while and what you're attemting to do is essentially impossible, particularly if you have any hope of having the audio sound the least bit natural after processing. It's my opinion that you just need to live with the audio as it exists and don't waste any time trying to fix it.
Given the other comments I've received, that's the conclusion I've come to. Thanks!
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