What is this noise and how to remove it?

[Kathy Smith]

Hi,

I have this specific "hum" and I can't figure out how to remove it. I have IzotopeRX, and the de-hum module doesn't do much. I can run spectral de-noise on it and get some of it removed. Obviously it affects the voice if I try to remove it completely. So, I'm hoping someone will be able to determine specifically, what it is and maybe tell me how to target just that noise.

https://www.dropbox.com/s/nbzyn4htea...Noise.wav?dl=0


Thank you
Kathy

[Battle Vaughan]

If the file I downloaded is an accurate measure of the sample, it seems to be a very low level base noise that probably could be ignored, as -70 dB is pretty small. This kind of noise can be from normal electronic noise in the recording devices, background rumble in the venue of the recording, etc. My home, with even with a small and absorbent room, with everything electrical turned off, has a constant -52dB rumble much like this. Again, if the levels in the sample are the levels you are worried about, I don't think they are much of a problem. You are correct, de-hum is for a specific frequency and its harmonics; this is a broad-range random noise from near 0 to around 17khz, and that won't help. You could do a sample and remove using a regular noise removal tool if you feel it's necessary. The capture shows what looks to me like a typical random noise pattern that is, to some extent, always present in a recording.

[Rick Reineke]

The noise is broadband so a hum remover tool and would not work well in this scenario. 'Hum' removal tools typically work @ 50 or 60Hz and the pertinent harmonics.
The source file's noise is around -60dBFS, which should be inaudible for most playback situations, unless cranking the monitor volume to abnormal high levels or normalizing just the noise with no other content. The audio on the frequency spectrum graph was normalized to show the frequencies clearly.

[Graham Bernard]

So many tracks. What am I looking at here? I've got it in iZoRX10 Advanced and I can't figure out what I should be focussing on. Please explain.

https://www.dvinfo.net/forum/attachm...1&d=1671605502

[Graham Bernard]

OK, RX Spec Analyser giving -75, not bad at all. And now I "see" the other streams. Just what they are from your capture, like to know. But, it all depends on just what it is you're attempting to hunt down. Are you purely wanting to ascertain just where these low dbs are coming from? Curiosity? Is it impinging on your Project? Are you wanting something less than -75? Are you searching for what could be making this type of noise?

https://www.dvinfo.net/forum/attachm...1&d=1671606161

Nice project, but I need more of your premise for just what you are searching for - please?

[Andrew Smith]

We really need a sample of your problem audio in a file that also has the content you want to keep, not just the problem noise only. Too many unknowns with the file you have supplied.

Andrew

[Charles Papert]

I used the AI-based process at audostudio.com for some problem tracks recently and it was pretty astonishingly good. You can process up to 20 minutes free as a sample. Very few settings but quite robust.

This was the test clip I did when first trying it out, where we weren't able to turn off the exceptionally noisy coolers behind a bar during a shoot. My post-production mixer couldn't match this with Izotope and has since used Audo on a number of projects, he says while it isn't always perfect, overall it is a huge time-saver.

https://www.dropbox.com/s/c22hdd03aq...t%202.mov?dl=0

[Graham Bernard]

Originally Posted by Andrew Smith

We really need a sample of your problem audio in a file that also has the content you want to keep, not just the problem noise only. Too many unknowns with the file you have supplied.

Andrew

Indeed.

It would be like me being given a Ball of Sheep’s wool, a Knitting Pattern and needles and then being told to make a pair of socks. But, in this instance, I’ve got the finished product and am now being told to come up with the knitting pattern.

I would dearly love the original file and just what it is that needs to be done. Hence my questions above and the motivation from Kathy just what it is she’s wanting. To produce nicer sounding audio, or, to determine what is making that noise.

Oh and BTW, I can’t knit.

.

[Christopher Young]

Originally Posted by Kathy Smith

I have this specific "hum" and I can't figure out how to remove it.

Upload a full file with the voice. Very hard to ascertain anything from the download. Sure, a few of us would have a look at it for you.

Chris Young

[Paul R Johnson]

What are the circumstances of the recording? That sounds more like mechanically generated noise than electronic noise? What are we actually listneing to? The sound of your preamp when nothing is plugged in? The sound of an empty room, via a mic .... or what? As everyone has said, it's extremely low, but then we've all normalised it to an annoying sound, but that's probably unrealistic? what are we listening to, recorded on what?

[Battle Vaughan]

Kathy, I should have mentioned in my reply that if you are worried about the effect on your voice content from removing this very small signal, it should have no practical effect. It is a fairly even signal across the entire vocal range, so removing it would just, at most, reduce the amplitude of the content by a tiny amount. An ordinary noise-removal effect (sample and remove) would do the trick. Simple answer, try it and see. You are correct that noise removal can affect content --- if it is a significant part of the signal, and particularly if over a narrow frequency range; removing a spike like that leaves a "hole." But this is a different animal.

[Christopher Young]

Originally Posted by Kathy Smith

I have this specific "hum" and I can't figure out how to remove it. I have IzotopeRX, and the de-hum module doesn't do much.

Whatever the noise is, it's a combination of things.

Track #1 has two channels, both left and right tracks, which appear to be dual mono and appear to be identical to each other.

Track #2 is showing on both channels, but appears to be summed mono.

Tracks 3 & 4 are purely White Noise. Track #3 showing on both left and right channels, and track #4 only on the left channel.

If I had the job of processing this "audio" I would totally lose tracks #3 and #4 as they are purely "noise". I would ditch Track #2 as it appears to be a summed mono version of what is on Track #1.

Finally, looking at Track #1's two channels, I could clean this up very quickly with Sound Soap, I think? Not having the associated audio with this 'noise' makes it hard to come to a definitive conclusion, but I have cleaned up this sort of noise quite successfully in the past.

Chris Young

BIAS SoundSoap Pro 2 Promo/Tutorial Video - YouTube

[Kathy Smith]

Hi All,

Thanks for all the replies. I think I'm obsessing over nothing. I think this is the room noise that I'm hearing (the hum of the fluorescent bulbs, perhaps). I know you asked me for details but in the interest of everyone's time, I don't think it's worth discussing it, as I can't hear it when I don't listen on my monitoring headphones.
It actually turns out that I won't be using any of this recording. I'm not happy with the content.

Thank you everyone who jumped it to help.

Kathy

[Paul R Johnson]

Kathy - lots of people spent time on this for you, and you don't think it's worth discussing? That's a little rough, if you don't mind me saying so.

The thing to remember is that you haven't fixed it, diagnosed it, or done anything to prevent it happening on a track that IS important.

We tried.

For what it's worth - the audio format you recorded it in is very unusual? All thos summed and empty tracks? Maybe you are recording on something a bit strange? If the noise worried you enough to join a forum and post - the worry will still be there?

Happy Christmas

[Christopher Young]

C'est la vie, as they say.

Anyway... have a happy holiday season everyone.

Chris Young