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Old September 17th, 2007, 03:46 PM   #1
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How can I cleanup this background noise?

It almost sounds like wind noise, but this video was captured indoors. Any idea what caused it or suggestions on how to clean it up?

Thanks!

Using Adobe Premiere 2.0 with Soundbooth.
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File Type: wav noise_sample.wav (1.51 MB, 510 views)
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Old September 17th, 2007, 04:12 PM   #2
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Air conditioner noise or mic movement in the air, coupled with excessive distance between the speaker and the mic making one boost recording levels to get sufficient volume? There's a machinery-like hum in addition to that irregular snuffling sound.
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Old September 17th, 2007, 04:53 PM   #3
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That's a pretty lousy audio track. It sounds a little bit like someone was wearing a lav mic under a wool trench coat while practicing layups on a basketball court.

Anyway, here is a quick and dirty sample of your clip run through SoundSoap 2 using the 'learn noise' and 'remove rumble' but pretty much no real adjustment. It sounds a little better, but for the really loud knocks, you'll probably need to manually remove those and replace with room noise to clean it up a little better. I don't think you'll ever get anything pristine off of that track though. The source sounds pretty far away.


-Jon
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File Type: wav noise_sample_rev1.wav (1.50 MB, 364 views)
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Old September 18th, 2007, 11:06 AM   #4
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Sounds like some kind of handling noise. Possibly a foam windscreen bumping against the schockmount.
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Old September 18th, 2007, 12:19 PM   #5
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1) Apply reshoot filter. If that's not handy . . .

2) Get the speaker in clip to do a voice-over about what was happening or narrator.

Very little else that can be done effectively, I'm afraid. What the mic hears in an environment and what your ears hear are sometimes radically different. A good example why location scouting and testing are important.
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Old September 18th, 2007, 04:29 PM   #6
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Here's my quick'n'dirty fix-up using Sony Sound Forge 9.

- Used the Noise-Reduction filter
- Used Paragraphic EQ to knock-out some of the low hum
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File Type: wav noise_sample_gm.wav (1.50 MB, 373 views)
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Old September 18th, 2007, 04:53 PM   #7
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Guy's upload is a dramatic improvement on that clip. I can actually make out what the speaker is saying.


Now I'm almost thinking that the really loud noises are actually the footsteps of the speaker.


It makes me wonder if the mic that was used was one of those flat mics that lays on a floor or mounts to a wall and is used to capture general stage acoustics.

We have a local soundman who uses them regularly for a local community theater. He lays a few of them on the floor at the front of the stage so that they pick up the vocals of the actors when they are singing or speaking from just about anywhere on the stage, and for that purpose they work okay, to a degree....except when anyone takes a step, then the crashing boom overwhelms the rest of the audio, which make the whole thing a really big mess during a dance numbers.

You can't tell during live performances, but they get taped and broadcast on our local access station, and that's when you really hear spoken word audio that sounds a bit like the clip noted in the orginal post.

-Jon
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Old September 18th, 2007, 10:20 PM   #8
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Here's one...

Here's one I did quickly in Audition after a full day of editing sfx... tired ears, so it might be crap.
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File Type: wav noise_sample_fix.wav (1.51 MB, 280 views)
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Old September 18th, 2007, 11:15 PM   #9
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Just to keep the audio editor fest going....

Here's what I was able to do in Soundtrack Pro.

Cleaned up as best I could.

Introduced stock ambient room tone to take away some of the post clean up harshness.

-gb-
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File Type: wav noise_sample-STP.wav (1.51 MB, 270 views)
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Old September 20th, 2007, 10:11 PM   #10
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Quote:
Originally Posted by Ming Dong View Post
It almost sounds like wind noise, but this video was captured indoors. Any idea what caused it or suggestions on how to clean it up?

Thanks!

Using Adobe Premiere 2.0 with Soundbooth.
OK. Several ideas. An HVAC duct blowing air on the mic or a contaminated mic diapgragm. Can you record some of this noise in a quiet environment and post it so we can hear it better?

Regards,

Ty Ford
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Old September 20th, 2007, 10:56 PM   #11
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The main background noise I hear is 60Hz and harmonics from mains power, airconditioner compressor?, conducted into the environment by the building structure, noise from fans through air ducting, maybe some other AC appliances operating as well like overhead flouro lighting, chillers etc..

Other sounds seem to be brushing of foot movements on floor, desirable as part of the action.

The lower registers of the voice are not apparent, however perspectively this is valid for the viewpoint which I imagine to be about 15 feet from the person speaking.

Audition, Cool Edit Pro, Sound Forge and others should have a preset filter for 60Hz and harmonics in the equaliser if my fading memory is correct.

My personal preference would be to apply this filter first, see if it helps, then take a clean noise sample, create a noise reduction profile then apply this to the clip.

If you have moved the camera and mike around to a new direction, you will need to create a new noise reduction profile for each setup.

When creating the noise reduction profile, try to avoid sampling the foot movements as these are also in the upper frequency range of your speaker's enunciation which will also be taken down along with the foot movements.

There are some dynamic effects presets available in Cool Edit Pro and should be there in Audition. Sometimes you can also get a bit of noise reduction by playing around with the stereo channels with varying delay settings by trying the available presets, then customising the one which sounds best. If it is a mono recording, dont let this discourage you from trying. If the camcorder has not already recorded the mono source to two tracks, copy the mono track to a second channel as a stereo pair then try it.

It may not be as silly as it seems as I have obtained some apparent, if not actual noise reduction in recovering audio from old scratched 78rpm records.

It will be well for you to consider the playback audio at the final destination of your footage and maybe customise your final mix to suit the reproducer, ie., 3 inch television speaker or sound system for a large screening room, maybe make two versions to give you some options.

If the sound is not conveniently recoverable, have the speaker record a voice-over, then drop the original sound recording to background and lay the new voice track over it.

You likely are more proficient at all of this than I so do not take too much notice of my comments.

Last edited by Bob Hart; September 20th, 2007 at 11:24 PM. Reason: added text.
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