Two characters in a dialogue have different background ambience

[ThisGeneration.net]

I am currently in the process of editing a feature film.  I have the audio leveled and normalized, but during the dialogue between two characters, they both have slightly different background noise. They were both filmed in the same location with a shotgun mic, so I have sound from two different directions that don't quite match up.  

Does anyone have any ideas on how to make the two backgrounds meld?

I have tried bringing into Adobe Audition and removing background noise, then adding only one character's ambiance back in, but that doesn't seem to work. I have also tried doubling up the room tone from both, but that makes everything a bit too loud.

Thanks,

Clay

[R Neil Haugen · Accepted solution]

Ouch! ... wow, just ... ouch!

So the sound person didn't quite stick the landing on making sure they had usable sound recorded ... that's always painful. But at this point, blending the two together is probably a bit past what most of us editor types can really do so it's unnoticeable.

And that's the need ... as if it's notable while watching, boom ... scene dies.

So you might be able to fix it, but realistically, this is perhaps needed to go to a good sound person, whoever is handling your total sound. I presume, with a feature, you have one ... ?

[ThisGeneration.net]

Ouch is right.  Especially when dealing with an A/C unit in a period piece.

It is a pretty low-budget production.  And as of yet, the sound person is still being hunted down.  That is probably the best option, as audio editing is pretty much out of my league.

Thanks

[Hutch Harris]

@ThisGeneration.net Knowing that its an A/C unit is good info. In theory you should be able to reduce the sound with a notch filter (check out this tutorial, covers this and a variety of other techniques.)

Additionally, you could either use a noise gate or manually adjust volume keyframes to further isolate the voices from background noise (i.e. volume up when character is speaking, back to zero when they aren't). Then stack these layers on top of your "background sound" layer (which maybe is something you've captured, or something you'll have to generate... or purchase). But in theory you'll wind up with 3 channels - (1) Voice 1, (2) Voice 2, (3) room noise. Hopefully will at least sound more natural than back-and-forth between room tones.

The only other thing I haven't seen mentioned, give the AI voice-enhancing tool a shot. Might wind up being too clean as its meant to replicate being right in front of a mic, but maybe at a low percentage it'll just help strip out the background noise.

[R Neil Haugen]

I've had the fun of talking with a couple good on-set sound people, and they are not fans of shotguns for dialog except as last-case backups.

Why? it's the focused thing ... they capture both a narrow cone in front of and typically behind!!!! the mic.

Think about that ... yea, that's going to pick up very different ambient sounds. And normally will require extra audio cleanup in post.

Which is why they have a wide array of mics they can hide close in, and 'bury' in clothing with protection against rustling/clothing sounds. It's quite impressive, what they have learned to do, and the specialized kit they have on-hand.

I watch say @PaulMurphy at work in some of his tutorials, and am just ... wowed ... his audio work is way above my paygrade! ... but he explains things so well.

Yea, at this point, it's whoever ends up being your sound person who's going to have to salvage that ...  situation.

[ThisGeneration.net]

Thank you for your answer.

We are just getting started, and good, reliable information is sometimes hard to find.

I appreciate you.

Clay

[R Neil Haugen]

This is a very complex, complicated process ... creating stories in motion images with sound. I came from a long pro stills career, how different can it be, right? Camera, lights, ok, so there's a mic now, so what?

So ... BAM. First couple things I tried shooting were total, abject failure. Images were pretty! Sound ... not great but ... well, it's ... isn't kinda ok usable ... um ... just ... no. Not at freaking all.

The School of Hard Knocks is an effective, if brutally painful, teaching academy.

Now, if I'm shooting something, the first thing considered is what kind of sound I will need before being 'done'. I make sure I get the sound righteous as possible, because I am so aware ... no usable sound, you ain't got zip.

The dialog parts you're missing could at need be added in VO work ... voice-overs. Bring the actors into a good sound room, with a screen of the scene playing, headphones ... and mics right in front of their chins.

They watch and re-speak what they did on set, go through it several times, and take the best bits.

Add in ambient sound from your sound library or create some new. 

Typical movie task, actually. Like ... foley, creating all the sounds from walking through gravel to opening doors to slamming refrigerator door to ... whatever is needed. Birds in the background ...  😉

[Richard M Knight]

You may have tried this, put each camera angle on a separate audio track and patch the holes with the correct room tone. Then gently cross fade at the end of each section, you won't need to completely fade out the track not being featured, -6db should be enough. It is easier using a hardware fader controller. When sound mixing I almost aways had couple of library atmosphere tracks running and this would cover most crossfades or noise reduction artifacts. 

[R Neil Haugen]

Adobe's sound app, Audition, has some good noise removal tools. For this kind of thing, there's one where you are looking at graphic image of the file's frequency response. You can go to a period of 'silence' where only the offending background noise is heard, select that, do a 'noise print', then have that removed from the entire clip.

[ThisGeneration.net]

Thank you. I have actually tried using Audition but wasn't able to fix the problem.

[R Neil Haugen]

What tools did you use?

They have a difference between waveform and ... multitrack, workflows, I think it is. The waveform shows a horizontal tall track, with a display similar to a colored waveform in Lumetri scopes.

With that one you can even select the noise with the mouse, in a 'quiet' segment, and use that selection as the noise print. And tell it to remove that only throughout the file. That I've found useful for AC noise before.

It's a 'destructive' workflow, that creates an entirely new file. 

[ThisGeneration.net]

I believe I used the waveform workflow.  I selected a segment with only the background problem, did a noise print, and followed the steps to remove the noise from the desired clip.  I think the reason it didn't work is the noise was so loud and behind semi-quiet dialog.  The project is an apologetics film about Creation vs. Evolution and includes a ton of conversations. Most, if not all, have the same issue.  Probably close to 1 hour of the 1:56 is taken up in direct conversations—each one with its own unique problem.

If all else fails, I may attempt to fade the audio between each character as much as possible and hopefully reduce the noticeability of the problems.

If you're interested in watching the trailer, we have it on our website ThisGeneration.Net 

I appreciate your help, time, and consideration.

Clay

[R Neil Haugen]

Oh wow, that would be a pain ... and would take really, really good DAW skills.

Or of course, getting the actors back in studio and doing VO ... which is a pain also. And may well not be possible, I know.