Deducting one noise from another at DVinfo.net

Go Back   DV Info Net > The Tools of DV and HD Production > All Things Audio

All Things Audio
Everything Audio, from acquisition to postproduction.


Reply
 
Thread Tools Search this Thread
Old June 1st, 2012, 09:50 AM   #1
Inner Circle
 
Join Date: Feb 2009
Location: Brisbane, Australia
Posts: 2,261
Deducting one noise from another

I've got one of those sneeze/cough removal scenarios.

I've recorded a presentation with both a lav mic on the speaker and also a crowd mic. And then someone lets off an almighty sneeze in the midst of it all. The offending sneeze is well caught on the crowd mic, and straddles through a word or two on the lapel mic.

So ... given that these two mics are synched on the timeline, is it possible to apply a deletion or 'minusing' of the crowd mic audio to the lapel mic audio?

Andrew
Andrew Smith is offline   Reply With Quote
Old June 1st, 2012, 09:56 AM   #2
Major Player
 
Join Date: May 2007
Location: San Jose, California
Posts: 858
Re: Deducting one noise from another

It will be very difficult, if not impossible to remove a sound like a sneeze just because it was recorded on two different microphones. I think you're thinking of the concept of phase cancellation, where the sounds are 180 degrees out of phase. 100% phase cancellation is very rare in the real world because of audio reflections, echoes, delays...etc.
You might have some luck if you can isolate that noise on a frequency spectrum view and then 'heal' the correct frequency (using a program like Soundbooth). If will be tricky, as a sneeze has a bit of white-noise quality to it.
A while back I did a tutorial on this:
Oren Arieli is offline   Reply With Quote
Old June 1st, 2012, 11:26 AM   #3
Trustee
 
Join Date: Aug 2008
Location: New York
Posts: 1,844
Re: Deducting one noise from another

If you can separate the tracks, overwrite the same or a similar sounding word from another part on the audience track from the event, even room tone may work. If the tracks are not separate, try finding the exact same word and in context. You could try a more expensive NR system like RX. YMMV in any case.
Rick Reineke is offline   Reply With Quote
Old June 1st, 2012, 11:41 AM   #4
Inner Circle
 
Join Date: Feb 2009
Location: Brisbane, Australia
Posts: 2,261
Re: Deducting one noise from another

Unfortunately it's right smack over the top of a word or two. Maybe I should have put it in as a featur request for Adobe? :-P

Thanks for your help.

Andrew
Andrew Smith is offline   Reply With Quote
Old June 5th, 2012, 12:21 AM   #5
Inner Circle
 
Join Date: Feb 2007
Location: Tucson AZ
Posts: 2,207
Re: Deducting one noise from another

I've had some good luck with Izotope RX but there are some sneezes that are impossible. I think there's a professional honker in every concert audience who's paid to wait for about a minute before cutting loose and ruining the take.
Jim Andrada is offline   Reply With Quote
Old June 5th, 2012, 01:53 AM   #6
Inner Circle
 
Join Date: Feb 2009
Location: Brisbane, Australia
Posts: 2,261
Re: Deducting one noise from another

True, true.

Was thinking of contacting the Izotope guys too. They have such cool software.

Thanks heaps.

Andrew
Andrew Smith is offline   Reply With Quote
Old June 5th, 2012, 05:22 AM   #7
Inner Circle
 
Join Date: Feb 2007
Location: Tucson AZ
Posts: 2,207
Re: Deducting one noise from another

I really like Izotope - had a situation once where the cellist in a chamber piece bumped the cello against the chair while playing - terrible noise. Was able to get it out without doing (noticeable) damage to the music.

Problem I always have with the professional sneezers that like to sit as close as possible to the mic is the length of the sneeze - some of them seem able to prolong it for several seconds and the longer it goes the harder it is to wipe it out.

And then there are the folks that must be related to a Canada Goose - they somehow figure out how to morph a 10 second sneeze into a string of coughs and sniffles and gasps long enough to cover up the Mozart Requiem. I often think it's some kind of mating call and they aren't going to stop until they get "satisfaction" of one form or another!

From the Guinness website...

Longest sneezing fit The longest recorded sneezing fit is that of Donna Griffiths (UK). She began sneezing on January 13, 1981 and sneezed an estimated one million times in the first 365 days. Her first sneeze-free day came 978 days later on September 16, 1983.

Fastest sneeze The highest speed at which expelled particles from a sneeze have been measured to travel is 103.6 mph (167 km/h).

Loudest snoring KOEre Walkert (Sweden), who suffers from the breathing disorder apnea, recorded peak snoring levels of 93 decibels on May 24, 1993.
Jim Andrada is offline   Reply With Quote
Old June 5th, 2012, 06:07 AM   #8
Trustee
 
Join Date: Dec 2007
Location: Glasgow, Scotland
Posts: 1,521
Re: Deducting one noise from another

Quote:
Originally Posted by Oren Arieli View Post
If will be tricky, as a sneeze has a bit of white-noise quality to it.
Isn't it more like "yellow/geen" noise in the worst cases? :-)

Any else had to wash a pop filter?
Colin McDonald is offline   Reply With Quote
Old June 5th, 2012, 06:21 AM   #9
Inner Circle
 
Join Date: Feb 2009
Location: Brisbane, Australia
Posts: 2,261
Re: Deducting one noise from another

Could be where the inspiration for Ghost Busters came from. :-)

Andrew
Andrew Smith is offline   Reply With Quote
Old June 5th, 2012, 02:43 PM   #10
Inner Circle
 
Join Date: Feb 2007
Location: Tucson AZ
Posts: 2,207
Re: Deducting one noise from another

@Colin

Yup! Sometimes think they need to be sterilized before and after each use. Sometimes I think this might be what turned the live cats into "dead cats".
Jim Andrada is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > All Things Audio

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 02:40 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network