NOISE REMOVAL QUESTION

[kozikowski]

<<<I know that you do not know much about Windows, but i think that the Volume control panel is pretty much standard in any system, even Linux No?>>>

No, the Mac one is much simpler and has its own little sound meter, so you can be sure of what you have. This is me going "AHHHHHH" into a microphone.

MacSoundPanel.jpg (20.77 KiB) Viewed 1560 times

The ones (plural) in linux change depending on whether you're using ALSA or ARTS sound services and even then it changes in each linux distribution. Our machines have a tool called artsTest that will tell you if there is sound on a connection or not. I think we have a modified one that's in stereo. The native one isn't.

Koz

[kozikowski]

There are three frequently encountered sound formats:

-- Mono -- a straight, single audio track.
-- Stereo, where two tracks carry the music plus direction information. The two tracks, left and right, are different so you can tell that the violins are coming from the left. The left speaker gets louder.

-- Two Track Mono. This is a hybrid of the first two. It appears to be stereo, there is a left and right track, but all the instruments are in the middle because there is no direction information -- the two tracks have exactly the same music.

When my computer records the built-in microphone, clearly mono (there's only one), I get a two track mono sound file. I set up the computer to do that because it's much easier to mix that with other "real" stereo clips and music and do music production and effects.

The fact that you can change the Left-Right slider and the noise goes up and down tells me that the microphone signal is being misinterpreted by the system -- or something is broken.

And now you're completely outside of my competency range.

Koz

[cosmiclight22]

OK I know it sounds confusing
I think you were trying to say that MONO on Audacity does not mean Audio MONO, but MONO track, am I right? And when the Balance slider is not in the middle between 2 channels, but toward one or the other, it is still Audio Stereo, at least I hope so lol

So I understand my questions did not make sense
Anyway, better to hear the sample, it might be easier to show you my problem, than my questions!!
thanks for this and attached are 2 files, one with Balance slider betw. channels all the way to left, and the 2nd file slider is in the middle between the 2 channels, which makes even louder noise in background
Hope you can tell me what to do to resolve this disturbance
Thanks
Annalena

[Trebor]

Back to the original topic of noise removal , you can attach a recording of your "zzz" noise to your next post,
5 - 10 seconds in WAV format (@ 44100Hz), half speech, half "silent" , e.g. ...

example made using windows recorder.wav

(567.99 KiB) Downloaded 85 times

Posting such a recording may help identify the problem.

[cosmiclight22]

Here is second file test
hope this helps

[billw58]

There are two things wrong with that recording. First is the hum. Second is the clipping. The signal from the microphone is being clipped before it gets into Audacity, and your voice is very badly distorted. That indicates that the gain of the microphone is turned up too high in the system sound control panel. This will also amplify any hum.

Back to the Windows experts to sort this one out.

-- Bill

[cosmiclight22]

Ok thanks a lot Bill
If the high gain means :MIC volume is high, I actually have placed it very low,
Wait to hear more
Thanks
Anna

[Trebor]

Try turning down the level (aka gain) sliders for the microphone in Windows "recording devices", (right click on the Windows loudspeaker icon where you control volume, or via "control panel", "hardware and sound", "manage audio devices") …

Adjust microphone levels on Windows Vista.jpg (39.41 KiB) Viewed 1512 times

select the recording device you are using, like I have selected "Microphone" above, then click to reveal it's "properties" (button bottom right) where their should be "level" slider(s) you can use to reduce the gain, (aka level, aka sensitivity), of the microphone.

The mains hum, (the deep buzzy sound like a Star-wars light sabre), is quite severe on your recording, moving the Windows microphone level slider control(s) down will help reduce it.


There are tricks to reduce mains hum on a recording, which I have used here …

CD Quality2_(before-after)_#2.mp3

(486.73 KiB) Downloaded 297 times

but it is much better not to have mains hum on the recording in the first place than to try and remove it afterwards.

[billw58]

Ok thanks a lot Bill
If the high gain means :MIC volume is high, I actually have placed it very low,
Wait to hear more
Thanks
Anna

As you'll note in Trebor's post, you need to adjust the mic volume in the Windows control panel. Turning down the recording volume slider in Audacity will not help, as the distortion occurs before the signal gets to Audacity.

-- Bill

[Trebor]

If the high gain means :MIC volume is high, I actually have placed it very low

After you have reduced the level slider(s) in Windows ”microphone properties”, to reduce the noise and distortion in your recording, (mains hum and clipping), you will probably have to increase the microphone level slider in Audacity from the “very low” setting to get a loud, (but undistorted), recording, i.e. this one …

Audacity microphone volume slider.png (12.26 KiB) Viewed 1513 times