'Noise Reduction' not working

It appears (amongst the other issues I have raised) that Noise Reduction tool is not working.

It simply does not reduce any noise.

I select a small section of the wave (where it shoiuld be ‘quiet’ or ‘silent’) - Effects - Noise Reduction - “Get Noise Profile”.
Then I select the entire wave, select Effects - NoiSE Reduction - leave all settings as pre-set and hit ‘ok’.
The “Applying Noise Reduction” timer appears as it shows the wave is being worked on… but when it finishes, the audio is exactly the same.

I have posted previously about other errors and I am still using the same Macbook to edit on Audacity 3.2.2

This issue is the same on all of the projects I am currently working on

What are the settings?

Works for me on W10 with 3.2.3

I used it successfully earlier this week on a recording from FM radio to remove/reduce the FM carrier hiss - 2 passes with Koz’ favoured 6.6.6 settings.


What are the settings?

Hi Steve, Please see screen shot…

I am unable to send you a screen shot because I get an error message when I attach the file:

“Sorry, the board attachment quota has been reached.”

Try this: https://drive.google.com/file/d/1TSGPz2UVjswYQLNnOo_5_UOvV8AMf4RC/view?usp=sharing

What are the settings?

Hi Steve - have sent link to you in a private message :slight_smile:

waxcylinder and koz are now recommending the parameters 6, 6, 6. In fact, it is expected Audacity will change to these as defaults in the next release.

Try these settings. If they don’t work for you, post a .WAV file illustrating the difficulty you are having.

Thanks. Steve said in a message to me that I possibly may be overdoing noise reduction. Noise Reduction creates bubbly metallic artefacts if applied too strongly, and that can be more irritating to listeners than a bit of hiss…

Is there a way that I can change / undo the noise reduction to return to the original state once I have saved and closed the project multiple times since using Noise reduction and other effects so that I can try the parameters 6, 6, 6?
I assume there isn’t but thought worth asking the question…

When the project is closed all “undo” data is permanently deleted.

I thought as much :unamused:

Is it still worth me trying with the new parameters, or would I be better to leave it now seeing as I have already used noise reduction?


Probably best to leave it as it is.

In future, keep a backup copy of the original unprocessed audio as a WAV file. Then, if you overdo an effect, you can go back to the backup.

Hi Steve,

I have a copy of the original WAV file and also save every few edits as a new project.

The issue is that I would be starting with an unedited file and I have spent many hours on editing the project.

Unless there was some way to use the original WAV (to use the suggested parameters in effects) and then somehow automatically transfer all of the editing from my latest version of the project?

Hi Steve,

Also, on that point - is there any way in Audacity to find out what effects have been used on a project after it has been closed? For instance is there a log that you can access with all edits?

As I think you expect, there isn’t a way to do that.

Short answer: No

Longer answer:

Some effects you will be able to hear, either because the effect itself is audible (for example: Reverb / Echo / Wahwah / …), or because the result can be measured (example: Normalize / Amplify), or because the effect is visible (example: Hard Clipping / Spectral Delete / …), or because the effect creates side effects / artefacts (example: Noise Reduction / MP3 encoding). When effects are subtle, or if there have been a lot of effects, it may be difficult or impossible to work out exactly what effects have been applied.

“Real-time” effects remain listed in the track’s effect stack, so you can see those by opening the project and looking at the effects attached to each track.

Some sound engineers keep a note book for each major project, in which they list all details about the project, including dates / times / place / equipment used / effects applied / …

Thank you, that is super helpful!

A log is a great idea

IIRC Paul Licameli may have started work on something called “Journalling” a while back but other stuff has got in the way for him in the meantime.

When I was doing a lot of audio editing work, my workflow was to create a new folder to contain the project and everything related to that project. Included in that folder would be a text file containing my production notes / log. My “off-site backups” would be copies of the entire folder, so if the worst happened (the studio burned down / plague / war / volcano / …) the project would survive, including all source files and production notes. (This was company policy).

Do you know if the journal was human readable or usable in any way for Audacity users? I tried looking at it in an older alpha version, but it just crashed, so I was unable to find out exactly what it was supposed to be.

Hey, thanks - I don’t have this under Tools on 3.2.2…