Hello all, I am new to Audacity so please be lenient when I do a mistake.
I just want to reduce some noise, and mark a piece of noise in my audio track. Then I go to Noise Reduction, where in the step 2 the following default values are set:
Noise reduction (db): 12
Sensitivity: 6.00
Frequency smoothing (bands): 0
Now I do as described in the wiki Step 1: Get Noise Profile. I do expect now, that the values for Step2 do change when I open the Noise Reduction the next time. But no change. In my opinion the Get Noise Profile function in Step 1 does not do anything. It always takes the Step 2 configuration.
Another example:
- adjust all the Step 2 values to 0 and run the function
- Edit → undo for undoing the filtering
- run again: Noise Reduction ->Get Noise Profile
- run Noise Reduction with the “profile”
Result: no change in the waveform at all !
There is no sign in the Tool where I can see that a noise profile has been learned, nor that the function “Get Noise Profile” has any effect on the parameters in Step 2. Do you have an idea what my mistake could be, or is it a bug?
Thanks and BR
Grimm
BS: opensuse 13.2 x64 with its Audacity 2.1.0
log:
08:58:56 PM: Audacity 2.1.0
08:58:56 PM: Trying to load FFmpeg libraries…
08:58:56 PM: Trying to load FFmpeg libraries from system paths. File name is ‘libavformat.so.56’.
08:58:56 PM: Checking for monolithic avformat from ‘libavformat.so.56’.
08:58:56 PM: avformat not monolithic
08:58:56 PM: Loading avutil from ‘/usr/lib64/libavutil.so.54.20.100’.
08:58:56 PM: Loading avcodec from ‘/usr/lib64/libavcodec.so.56.26.100’.
08:58:56 PM: Loading avformat from ‘libavformat.so.56’.
08:58:56 PM: Actual avutil path /usr/lib64/libavutil.so.54.20.100
08:58:56 PM: Actual avcodec path /usr/lib64/libavcodec.so.56.26.100
08:58:56 PM: Actual avformat path /usr/lib64/libavformat.so.56.25.101
08:58:56 PM: Importing symbols…
08:58:56 PM: All symbols loaded successfully. Initializing the library.
08:58:56 PM: Retrieving FFmpeg library version numbers:
08:58:56 PM: AVCodec version 0x381a64 - 56.26.100 (built against 0x381a64 - 56.26.100)
08:58:56 PM: AVFormat version 0x381965 - 56.25.101 (built against 0x381965 - 56.25.101)
08:58:56 PM: AVUtil version 0x361464 - 54.20.100 (built against 0x361464 - 54.20.100)
08:58:56 PM: FFmpeg libraries loaded successfully.
There are no dancing girls or parades when Noise Reduction learns a profile. It just does.
The blue waves may not change when you do a successful reduction. If the correction is in sounds lower volume than about -35dB, that won’t show up on the timeline. It can be said that if you see a significant change during Noise Reduction, you’re probably doing something wrong.
Listen to it. Or better yet, do a test where you noise reduce a portion of the show and listen to the difference when you roll over the boundary.
That’s not to say things are always perfect. If the profile step includes a little of your voice by accident, for one example, then Noise Reduction will try to remove your voice.
The other common mistake is that “noise” isn’t just “Stuff I Don’t Want.” Noise Reduction only works on sounds that do not change over time. That air conditioning fan? Gone. Gentle microphone hiss? History. That MetroBus driving by? Sorry, you’re stuck listening to the bus. This is why number 4 can kill your show.
The Four Horsemen of Audio Recording (reliable, time-tested ways to kill your show)
– 1. Echoes and room reverberation (Don’t record the show in your mum’s kitchen.)
– 2. Overload and Clipping (Sound that’s recorded too loud is permanently trashed.)
– 3. Compression Damage (Never do production in MP3.)
– 4. Background Sound (Don’t leave the TV on in the next room.)
Remember to select the whole track by clicking just above MUTE before you apply reduction. Otherwise nothing at all will happen.
That kills me about once a week.
Koz
You didn’t say what the show was. If you’re recording your speaking voice, then the Noise Reduction of the Beast might be helpful. Reduction values of 6, 6, 6. If that’s not quite enough, then 12, 6, 6.
If it’s music then you’re on your own. I don’t know any known, good, working settings for music.
Koz
No dancing girls? I am quite a bit disappointed now. 
I do digitalize some records/vinyls and there is a noise (and sometimes a clicking) in the recording. My sound card does recording with 96kHz sampling and I set up the 32bit float in audacity. The turntable was quite expensive with a quite good needle and I use quite a decent AKG headphone to listen to it.
When I set the parameters to 0 and start “get noise profile” and execute the filter with the learned profile (parameters still 0) then I can’t hear a difference. Why that? Why is the Step 1 not setting the Step 2 parameters?
If I do adjust the parameters (Step 2) by myself, it works as expected and the noise gets reduced. But the learned profile I can not hear for some reason.
My last reply is not visible for some reason.
I do record some old records/vinyl. The equipment for that is quite good, the records very old and not so good. When I set the Step 2 parameters to 0 and do the “Get Noise Profile” and execute this profile next time (with parameters 0), then I can just see a slight difference in the waveform but its not hear able. When I adjust the Step 2 parameters, to some values I can of course hear the difference. But I am lazy and thought I can use the profiling thing. But for this I can’t find evidence that it works.
Your posts are moderated until we’re sure you’re not going to try and sell us Male Enhancing Products if you get my drift.
Clicks and pops aren’t “noise.” Those are one-time events. It’s not likely, but it’s possible to have one pop in the whole record, so it fails the idea of continuous noise like a fan or pump.
Sometimes you can get rid of minor “groove hiss” with noise reduction, but vinyl records are a special class.
http://manual.audacityteam.org/o/man/tutorial_copying_tapes_lps_or_minidiscs_to_cd.html
Also search for Brian Davies Click Repair or something like that. It’s not Audacity software, but widely reported to do a very good job at vinyl processing.
Koz
Hehe, I understand. Thanks by the way for your fast reply.
I know, the clicks and pops I need to be filtered differently. I will play a bit with the plug-ins and see how far I come. Thanks also for the link and the hint to the other SW, I will check that later.
Best Regards