Topic: Audience Noise Removal - Audacity 2.2.1

[rockphantom]

Howdy,

I've successfully captured the Whitesnake/Dead Daisies show at the Moody Theater in Austin, Texas last night.

I've listened to my recording for a few minutes this morning and was pleased with the results.
However, there was an obnoxious screaming woman behind me who was going off like a cat in heat for the duration of the performance.
I'm a relatively new Audacity user and was wondering if there was a way to remove audience noise (banshee like screams) without damaging the source material.

If you take a look at these two Audacity screen shots you can easily see the peaks produced by these screams.
Note: I merged and normalized the WAV files to -1.0db.

If someone could please provide me with the information I need or point me in the right direction, I'd appreciate it.
I'd like to remove as much of this noise as possible before sharing the recording.

Thank You!

[EarlyMorningRain]

sorry I do not use Audacity but perhaps the approach would be the same ??

Using Sound Forge, I zoom in on the suspect area(s), highlight the offending material (the lady behind you) and attenuate down a couple of db's or so. Then give it a listen and tweak and needed. Then wash/rinse/repeat the process for any other affected areas.

But certainly wait for others to chime in with their first hand knowledge before taking my advice.

[dean]

sorry I do not use Audacity but perhaps the approach would be the same ??

Using Sound Forge, I zoom in on the suspect area(s), highlight the offending material (the lady behind you) and attenuate down a couple of db's or so. Then give it a listen and tweak and needed. Then wash/rinse/repeat the process for any other affected areas.

But certainly wait for others to chime in with their first hand knowledge before taking my advice.

This is my approach using Audacity.  It's clunky, at best, but works.  I'm hoping another Audacity user has a better process...

[Life In Rewind]

sorry I do not use Audacity but perhaps the approach would be the same ??

Using Sound Forge, I zoom in on the suspect area(s), highlight the offending material (the lady behind you) and attenuate down a couple of db's or so. Then give it a listen and tweak and needed. Then wash/rinse/repeat the process for any other affected areas.

But certainly wait for others to chime in with their first hand knowledge before taking my advice.

This is my approach using Audacity.  It's clunky, at best, but works.  I'm hoping another Audacity user has a better process...

Agree with above posts...pretty much the only way of handling it.

You'll want to do this BEFORE you normalize...by looks of it - she's the loudest thing...

[dean]

sorry I do not use Audacity but perhaps the approach would be the same ??

Using Sound Forge, I zoom in on the suspect area(s), highlight the offending material (the lady behind you) and attenuate down a couple of db's or so. Then give it a listen and tweak and needed. Then wash/rinse/repeat the process for any other affected areas.

But certainly wait for others to chime in with their first hand knowledge before taking my advice.

This is my approach using Audacity.  It's clunky, at best, but works.  I'm hoping another Audacity user has a better process...

Agree with above posts...pretty much the only way of handling it.

You'll want to do this BEFORE you normalize...

Without question, do this before normalizing.

[rockphantom]

Thank you all for your replies! A friend suggested I do hard limiting of the master WAV prior to normalizing. Should I attempt to eliminate the screams first?
I've never attempted to hard limit a recording.

[Gutbucket]

Quickly reducing the level during the offensive sound is about as good as you can do easily.  If the the visible peaks far louder than the music are your caterwauler, you can easily reduce those to the same level as the music and make them at least less invasive, probably without introducing other obvious audible artifact.   You may be able to reduce a bit further, but the reduction will become audible as the music level suddenly decreases, sounding much like a limiter cutting in (which is what it is- a manual peak limiter applied just to those instances).

With more work you can sometimes do some interesting tricks-
If mostly on one side, you can copy the opposite channel and do a quick cross-fade to two-channel mono and back.  That can be less invasive than reducing signal level during the wail, since only the stereo imaging is effected and not the level of the music.

Similarly you can use Mid/Side techniques to cross-fade to more Mid-dominated mono or Side-dominated mono if the offense is in the center or the more diffuse ambience.  There is a Michael Gerzon paper from 1990 about various kinds of cross-fading tricks to do this, back in the analog mixing era, by setting up routings so a single fader could be rapidly moved in real-time to more easily reduce pops, dropouts, and these kind of unwanted noises during a dub with minimal artifacts. http://www.audiosignal.co.uk/Resources/Outside_the_mix_A4.pdf

The best modern approach to this are probably noise reduction commonly tools referred to as spectral editing tools.  They allow one to draw envelopes around offending noises on a spectral display that plots frequency against time, and apply clever algorithms to partly reconstruct the cut-out frequency bits from the unaffected surrounding time/frequency material.  Izotope RX is probably the most well known, can run standalone or as a VST I think, and is rather pricey.  Samplitude has this capability but is an full featured audio editing program.  Sony offers one I think, and I'm sure there are others, including very expensive tools from CEDAR and the like.  These are fantastic tools for this kind of thing which can near magically remove coughs and other noises, but they are complex and tend to be pricy unless included in the editor's built-in tools.

[thunderbolt]

I use hard limiting when stealthing at sit down festivals.  Play around with the settings.  I can get it to a point where I can pretty much highlight the whole set and squelch the cheers and claps to a very tolerable level.  This is for jazz concerts, however, which is a different thing than loud rock.

[Gutbucket]

Thank you all for your replies! A friend suggested I do hard limiting of the master WAV prior to normalizing. Should I attempt to eliminate the screams first?
I've never attempted to hard limit a recording.

 
If the loud screams represent the highest signal portions of the recording, you are manually limiting them when you zoom in and reduce their level.  A properly set limiter does the same thing, but may also effect the sound of other portions.  Setting it properly can often times be more difficult than just zooming in and drawing volume envelopes, or selection the region and reducing level, or however that's accomplished in Audacity.

Normalize last, after the noises are fixed to your satisfaction and everything else you want to do is done, other than tracking.

[morst]

I would say leave it alone.

The best thing you can do is to forget what she looks like, and come back to the master in a year with some perspective.

[voltronic]

Be very careful when using the hard limiter in Audacity.  I used to use it to knock down clapping, but for anything else I'd advise against it, as it is "haircutting" (clipping) the waveform, making your screamer softer but now horribly distorted. 
(Not to pull this OT, but here's how I knock down applause, and it sounds much better than a hard limiter.)

While maybe not the best either, you could try using the compressor.  Set the threshold to just above the level of the surrounding music, and then un-check the "make-up gain" setting.  This will also compress the music underneath the screamer, but if it's brief it might be an OK.  You could combine this with MS processing as Gutbucket suggests if the screamer is in the middle of the image, and you might do less damage to the music - squash the middle; leave the sides alone.  That's beyond Audacity's capabilities though...

Gutbucket is right that Izotope RX is the tool that allows you to really fix these things - the Spectral Editing he's describing is very powerful.  It's not all that cheap, but I find RX to be well worth it for what it can do.

If you'd be willing to post a clip, I'm sure a few of us here would be willing to have a crack at it.

[thunderbolt]

I should clarify.  The beauty of jazz is that most of the time there is a short gap before applause.  I hard limit what is essentially clapping/screaming, not music.

[voltronic]

I should clarify.  The beauty of jazz is that most of the time there is a short gap before applause.  I hard limit what is essentially clapping/screaming, not music.

I have abandoned hard limiting even for clapping, because the clipping distortion is so audible (at least if you use Audacity's hard limiter).  I only attenuate clapping using one of the methods I describe in that thread I linked from a couple years ago.

[aaronji]

I should clarify.  The beauty of jazz is that most of the time there is a short gap before applause.  I hard limit what is essentially clapping/screaming, not music.

There is that after solo applause sometimes, though, while music is still going on...

I use the "Hard Limiting (process)" in Audition to deal with this problem too.  Fast attack and release times.  Works very well unless you really over-do it.  I prefer this to envelopes because the levels of the underlying music are unchanged.

[rockphantom]

Thank you everyone for your advice.

Here is a FLAC sample of the second song of the night.
Screams at the beginning and end.

https://www.sendspace.com/filegroup/kO%2BzvX0CMs4psvg3xV1KlA

I can post a sample of a tune where the woman is screaming every 30 seconds if anyone is interested.

Here is lineage of my recording: Soundman OKM II Rock Binaural Omnidirectional Microphone - > A3 Adapter preamp -> Sony PCM-M10 (Line In) -> 24/96 WAV