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Removing or Reducing Hum or static from files

Posted: Mon May 21, 2018 4:23 pm
by rbendtzen
Hi.

Is it possible for me to completely remove or reduce to any extent the sounds of constant humming and/or static from audio files?

The kind of hum I am talking about refers to files that have a high or low pitch tone heard underneath the main audio of the file.

Also, can I remove or reduce static sounds from audio files? You know, like crackles from a film's audio track.

Please let me know. Thank you very much.

Rob Bendtzen

Re: Removing or Reducing Hum or static from files

Posted: Tue May 22, 2018 1:50 am
by DougDbug
Is it possible for me to completely remove or reduce to any extent the sounds of constant humming and/or static from audio files?

The kind of hum I am talking about refers to files that have a high or low pitch tone heard underneath the main audio of the file.
Yes, but there can be artifacts (side effects), especially if the noise is bad. Pros still record in soundproof studios with good equipment because there's only so much you can do, even with expensive-pro software.

If you have power line hum/buzz (or if you otherwise know the frequency) you can apply a notch filter (a narrow bandstop filter) at the line frequency, and possibly at the harmonics. For example, if you're in North America you can notch-out 60Hz, and possibly 120Hz, and 180Hz, etc., until you have acceptable results. (A notch filter is not prone to artifacts.)

Or, you can try the Noise Reduction filter. Noise Reduction works best when you copy a "noise fingerprint" into the clipboard, then choose "Use Clipboard" as your "Reduction Envelope". Noise reduction is prone to artifacts... It works best when you have a very low level background noise... It works best when you don't really need it...
Also, can I remove or reduce static sounds from audio files? You know, like crackles from a film's audio track.
That can be trickier. There is a Pop/Click filter and a Smoother filter.

There are also special purpose programs for cleaning-up digitized vinyl records.
Wave Corrector is now FREE. Wave Repair ($30 USD) has the advantaged/disadvantage of only "touching" the audio where you identify a defect. It has several different repair modes and usually one of these modes/methods can "perfectly" remove a click/pop, but of course it can take LOTS of time.

Re: Removing or Reducing Hum or static from files

Posted: Fri May 24, 2019 2:34 pm
by FonsCarver
Hi...i saw this and in my case the static noise gets worse as the track goes on but then near the end it disappears. And as I said it wasn’t like that in the FOH at all. Perhaps the radio receiver picked up some interference from another nearby channel?