Suppress GSM bzzzz background noise

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kitou
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Suppress GSM bzzzz background noise

Post by kitou » Thu Dec 27, 2012 5:41 pm

Hi

I have a conversation record with an awful bzzzzz background noise coming from a GSM too near from the recording machine.
How do you thing I can reduce it, with way for filtering ? I'm a new user of Audacity.

regards and happy new year coming soon

Chris

kozikowski
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Re: Suppress GSM bzzzz background noise

Post by kozikowski » Thu Dec 27, 2012 8:11 pm

Probably not, but if you want to take a shot at it, Effect > Noise Removal.

It works in two steps. Drag-select a portion of buzz by itself. No voices. Run the tool and Get Profile.

Select some of the actual show, run the tool again and apply it. Audacity will try to remove whatever you captured in the profile from the show.

No, it's not that easy and setting the sliders is something of an art form.

http://manual.audacityteam.org/o/man/noise_removal.html

Are you going to tell us how you were trying to record your cellphone? It's not that easy and we're always up for new ideas.

Koz

Trebor
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Re: Suppress GSM bzzzz background noise

Post by Trebor » Fri Dec 28, 2012 12:06 am

kozikowski wrote:Probably not
I second that, the GSM buzzy pulse occupies all of the sound spectrum ...
GSM buzzy pulses cover all of the sound spectrum 8¬(.gif
GSM buzzy pulses cover all of the sound spectrum 8¬(.gif (125.55 KiB) Viewed 2220 times
If the buzz coincides with the sound you want to keep (voices) they can't be removed without taking the voice too.

kozikowski
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Re: Suppress GSM bzzzz background noise

Post by kozikowski » Fri Dec 28, 2012 1:52 am

All these things I was going to get to while I was on holiday/vacation....

I never tried out my telephone recording system on a cellphone and I never wrote up the one I got to work on a landline.

One of these days.

Koz

kitou
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Re: Suppress GSM bzzzz background noise

Post by kitou » Fri Dec 28, 2012 8:53 am

In fact, I was not recording the gsm but a conversation meeting. At the beginning, the record is good. But after a while, the parasite gsm bzzzz background sound appears; i think someone moved its GSM from his pocket and put it in the table near the recorder, so that i have the wave parasiting sound (although the GSM is muted).

Here attached the spectrum, without then with the buzzy parasite sound :(
Attachments
spectrum.jpg
spectrum.jpg (235.58 KiB) Viewed 2197 times

Trebor
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Re: Suppress GSM bzzzz background noise

Post by Trebor » Fri Dec 28, 2012 4:05 pm

kitou wrote:Here attached the spectrum ...
Audacity has another kind of spectrogram display which can be selected from the "track drop-down menu" as an alternative to the waveform display ... http://manual.audacityteam.org/man/Track_Drop-Down_Menu

But when it comes to trying to remove the GSM noise when it coincides with speech you are "fouetter un cheval mort".

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