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What is causing these vibrations?

Posted: Mon Aug 03, 2015 1:43 pm
by TheRhysWyrill
Hi,

I recently appear to have been getting this issue (As seen in the attachment below), I'm not exactly sure what is causing this & it appears to happen at random intervals but i can't quite pinpoint the issue, just to be clear I know it is not the device I am using to record as i got it brand new out of the box this morning. The weirdest thing about this issue is it sounds no different to any of the other noise in the clip although because I use noise removal it mostly severely deteriorates the audio quality of the track.

The version of Windows I'm using is 8.1 & Audacity version is 2.0.6 (Tried with 2.1.1 but unfortunately the problem persists).

Thank you for taking the time to read this.

Re: What is causing this issue?

Posted: Mon Aug 03, 2015 2:02 pm
by Gale Andrews
Audacity only records the signal and noise it receives. What exactly are you trying to record, using what equipment (makes and model numbers, please)?

What does your screenshot represent? Is it noise between words or songs, and is that before or after noise removal? And is the peak in the screenshot some unwanted random noise like a click? If so, how often do those random noises occur?

Can you post an audio sample that we can hear? See How to post an audio sample.

If there are random clicks in what you are recording, check your cables are tight both ends and try increasing Audio to buffer at Edit > Preferences... (Recording section). Try turning other applications off. Disconnect the internet, turn the WiFi off then turn your anti-virus off.


Gale

Re: What is causing this issue?

Posted: Mon Aug 03, 2015 2:21 pm
by TheRhysWyrill
I'm trying to record commentary, the equipment i'm using is the Sony ECM-CS3 Condenser Mic.

The screenshot was supposed to represent the random waveforms that occur at the very start of the clip & about 5 or so seconds into the clip with nothing to make them occur although I realise now that a screenshot does not clearly illustrate that.

I have 2 audio samples, one before applying noise removal & one after applying noise removal, both clips have been normalised.

Thanks.

Re: What is causing this issue?

Posted: Mon Aug 03, 2015 4:32 pm
by Paul L
Hello,

I am not sure what your complaint is from reading, but from listening, the problem seems to be that some click sounds in "before" now have an audible whooshing noise in them "after." Is that it?

Please be specific about the slider settings you tried for Noise Removal and for new Noise Reduction.

My guess from looking at the spectrograms is that for 2.0.6 your attack and decay settings are too long. But 2.1.1 has no such settings, so I don't understand what your complaint is there.

Some experience has shown that in 2.1.0 and later Noise Reduction, the default setting of 0 for frequency smoothing gives unsatisfactory results for voice, especially where there are breaths, but it's better turned to 3 or more.

Re: What is causing this issue?

Posted: Mon Aug 03, 2015 6:42 pm
by Gale Andrews
Paul L wrote:I am not sure what your complaint is from reading, but from listening, the problem seems to be that some click sounds in "before" now have an audible whooshing noise in them "after." Is that it?
Clearly that is a concern here, and in this case I did not find that increasing frequency smoothing in 2.1.1 helped unless it was so high that it affected the voice.

Noise Removal is only meant for steady noise. It is not really designed for random noises like the clicks that are exposed (and made more whooshy) by removing the noise.

The clicks are really too broad for Audacity's Click Removal. You may be better to work on preventing the clicks and/or reducing the noise (see my suggestions about the clicks). Or simply select passages between paragraphs and reduce their volume with Effect > Amplify... so you only hear a little bit of steady noise.

Where are you connecting this mic - into the mic port of the computer? You could look in the mic port properties on the Recording tab of Windows Sound (right-click over the mic port) to see if you can reduce the gain or "boost" on the mic or to see if enabling any noise suppression offered there might help. But enhancements settings like noise suppression can make things worse by introducing fades.


Gale

Re: What is causing this issue?

Posted: Mon Aug 03, 2015 9:59 pm
by Paul L
Gale Andrews wrote:
Paul L wrote:I am not sure what your complaint is from reading, but from listening, the problem seems to be that some click sounds in "before" now have an audible whooshing noise in them "after." Is that it?
Clearly that is a concern here, and in this case I did not find that increasing frequency smoothing in 2.1.1 helped unless it was so high that it affected the voice.
Gale
I am confused, 2.0.6 noise removal made that bad effect. I do not hear it with 2.1.0 if I use settings 12 - 6 - 0 or 12 - 6 - 6.

Re: What is causing this issue?

Posted: Tue Aug 04, 2015 4:34 am
by kozikowski
I have found that in the case of vocal performances and audiobook production under Audacity 2.1.0 and 2.1.1, the noise reduction of the beast (6, 6, 6) works remarkably well and leaves few if any artifacts. If you need more serious reduction, the next two levels 12, 6, 6 and 18, 6, 6 may be needed, Past that you have to fix your microphone, computer or environment (or possibly all three).

The music people may need other settings, but for vocal performances, this is pretty much a gift from the angels.

One very common problem as in above posts is the definition of noise. Noise is any constant undesirable sound that doesn't change over the course of the performance. Computer fan noise, air conditioning whine and microphone hum are "noise," but vinyl record popping, metrobusses driving past, thunder, dogs barking, and babies crying are not.

So noise is not just "stuff I don't like."

Once you establish the profile or noise sample at the beginning of the performance, noise reduction will go charging down the performance (or whatever you selected) looking for that one, single, exact noise. It doesn't speak English or know what a baby, dog, metrobus, or weather are. It's pretty stupid that way.

It also super important that your selected profile have only noise in it and nothing else. If you get a little voice in the profile by accident, Noise Reduction will destroy the show.

Koz

Re: What is causing this issue?

Posted: Tue Aug 04, 2015 3:32 pm
by TheRhysWyrill
I've tried all the above posts (Thank you for the help btw) but unfortunately they have all had little to no effect.

As weird as this may sound I think the underlying cause of the issue is due to vibration that the microphone is somehow picking up.

As an example I recorded a 10 second sample of "Total" silence which when listened to shows no audible disruption etc, however there is clearly something causing the waveforms to become so erratic.

Re: What is causing this issue?

Posted: Tue Aug 04, 2015 5:00 pm
by Gale Andrews
TheRhysWyrill wrote:I've tried all the above posts (Thank you for the help btw) but unfortunately they have all had little to no effect.
So you are connecting the mic to the mic port of the computer?
TheRhysWyrill wrote:As weird as this may sound I think the underlying cause of the issue is due to vibration that the microphone is somehow picking up.

As an example I recorded a 10 second sample of "Total" silence which when listened to shows no audible disruption etc, however there is clearly something causing the waveforms to become so erratic.
I agree the waveforms of the noise are a little more jagged than might be expected but you only have two fairly quiet clicks embedded in the noise either side of 7 seconds - if this had been the noise you had before it should have caused less problem for Noise Reduction.

The noise profile should not include any embedded clicks. Try zooming in a little and select a noise area for the profile that looks flat and centered over the 0.0 line.

Do I presume you are wearing this mic? Is the cord rubbing against your clothes or something else?


Gale

Re: What is causing this issue?

Posted: Tue Aug 04, 2015 5:08 pm
by TheRhysWyrill
Yes, the microphone is connected to my computers combination jack using a Y splitter adapter (Tried the same test without the adapter, same issue arises so it's not the adapter).

Upon further investigation I have realised that the waveforms only seem to be that way if I'm recording directly from my computer, I did the same test recording but instead using my phone & imported the audio file to Audacity & the waveform was completely flat, not jagged & erratic as has been shown in previous posts.

I'm not sure whether I hear these clicks at 7 seconds, though that could just be my ears.

Yes I am wearing this microphone, it's clipped to my shirt, the cord & everything however are not rubbing on anything.