Noise Reduction Question

[gnomeplanet]

Hi - I'm using Windows 10 and Audacity 2.1.2 .exe downloaded from the main site. I have a question about Noise Reduction. I've been following the instructions on http://manual.audacityteam.org/man/noise_reduction.html
I have my audio on the screen, and select a section with just noise in. Click 'Effect > Noise Reduction > Get Noise Profile'. The Noise window closes. I then clear my selection and select the whole track. Click 'Effect > Noise Reduction > OK', and the noise reduction slowly happens, BUT my sound waveform on screen has disappeared!! I can still see the time-line, and press play and hear the audio, but I cannot see it, which means I can't now do any editing to remove the noise section at the front of the track. I have to Export to mp3, then restart Audacity and then reload the .mp3 file to be able to see it and edit it.

Obviously I'm being stupid and have not pressed the correct buttons, but I can't figure out which one!! The Help page mentions 'Effect > Repeat Noise Reduction', but I don't have that.

I hope someone can help.

[kozikowski]

I don't know that you are doing anything wrong. I've never heard of it doing that.

One of the things I do when I read of a problem is think what would I do to force that to happen. I don't know that I can force that to happen. If Noise Reduction really did suppress the show, then you wouldn't be able to hear anything and you would not be able to rescue it by exporting.

Just to cover it, you did get Audacity from here, right?

http://www.audacityteam.org/download/windows/

And when you do INFO, it does say Audacity 2.1.2, those exact numbers?

Koz

[gnomeplanet]

Yes, I did get Audacity from this site, and the version is 2.1.2. I might mention that I obtained the audio in the first place from a USB cassette recorder, which comes up as 'Microphone Array USB PnP' on the input selector.

[DVDdoug]

How bad is the noise and what does it sound like?

Noise reduction is designed to work with low-level background noises. I've never tried it on a loud noise, but it's possible that it would remove the noise and everything else too...

I have to Export to mp3, then restart Audacity and then reload the .mp3 file to be able to see it and edit it.

Are you sure you're not re-opening the original MP3? Are you re-naming it? i.e. Add "noise reduced" to the name...

[kozikowski]

Yeah, see? Contradictory symptoms. If Noise Reduction was a little too nuts when it worked, you would lose the blue waves and the ability to hear the show.

????

Koz

[Gale Andrews]

Post a sample (without any effect applied to it) that contains a second or so of noise only, then the noise with the audio you want to keep. See How to post an audio sample.


Gale

[Edgar]

I have seen this happen (wave image gone but still able to hear sound) - years ago, pre-2.0 - after applying an effect (but I don't remember which effect although I do use Noise Removal/Noise Reduction a lot). I was able to get it to refresh the image by doing a "fit to window" but not by zooming in or zooming out. I have not seen it in years; at the time I was running a very old video card which I have since replaced.

[kozikowski]

So the poster is a celebrity.

@gnomeplanet - if you rejoin the thread, please do post a sample of the work as above.

Koz