Audacity Forum

I just successfully recorded my first project (one side of an album). It plays back great, but I can't get the click removal or noise removal tools to work! I magnify and highlight the offending pop, use the menu to select click removal or noise removal, but no matter how I try to set the sensitivity levels, the previews sound exactly the same as the original pop! Repeated attempts to remove the pop show absolutely no effect. What am I doing wrong? I tried the editing before I saved the project and after I saved it -- same result. Any help would be appreciated!
Thanks, GeeZee

Those two tools are a little more involved and complicated than you would think.

Try this. If you know where the click is (it's not much of a mystery. It's usually the biggest thing in the waveform), then select just the click spike waveform and then click Edit, Silence.

Go back and play the clip through the effect. It should be gone.

Remove Nose is usually used to get rid of low constant background noise in an interview such as air conditioner or fan.

I think the click removal tool needs to see what the music is like before and after the click. If you select the click ahead of time, it can't do its job. I gotta look at this a little more. Can you post a little piece of the work that has a nice healthy pop in it? Say five or ten seconds with the pop in the middle?

Oh, and be careful when you save as a "Project." Projects aren't sound files. Projects are file managers that tell Audacity what to do with your capture clips. "Export" is the tool to use to walk away with a single sound file you can email to your sister in Schenectady. Or post on your web site for me.

Koz

I have had some trouble with this as well. And I have used the Silence tool to get rid of the clicks or pops from vinyl recordings. After I selected Silence, then played it back, the pop was gone. But when I zoomed back out and played a 6 second section of the recording that included the pop, it was still there. Slightly muffled and not as loud, but still there. These spikes in the waveform were so small I would have thought the Silence tool would take care of the problem.

Short Answer:
What is probably happening is that by creating the silence you are creating a slighlty disjoint waveform at the boundary(s) of the silence - Such a disjoin will cause a pop of its own - if you zoom in you may see the disjoin.

Long Answer:Personally I have never had much joy with the click removal effect in Audacity - at fisrt I tried the method that Koz suggests (creating a silence) or deleting the click - but neither of these gave really satisfactory results.

So what I have done is to remove them manually. Version 1.3 of Audacity is much better for this as the developers have added a new "Repair" effect - this will mend a broken portion of waveform, up to 128 samples, by interpolating from the neighbouring waveforms.

To use it you really need to zoom in (use the magnifying glass icon) to the level where you can see the individual samples (little dots will shoe on the waveform). Then select up to 128 samples 1.3.x has a counter display at the bottom to help with this - then click Effect/Repair (if you are doing a lot of repairs then so long as you don't use any other effect meanwhile then Repair will remain the current effect and you can use the Ctrl-R shortcut. In 1.2.x of Audacity you will have to instead use the pencil tool to redraw the waveform manually. It's probably worth testing the repair before moving to the next one.

BTW: a useful tip for finding the clicks is to use the "Spectrum" view of the project rather that "Waveform" - click on the little downward pointing triangle in the control box of the track to get a dropdown to do this. Clicks/pops will show up as strong bold vertical lines. But I recommend switching back to the Waveform view for the actual Repair.

If you get a really big click/pop that's bigger than 128 samples then you can try selecting the whole lot and deleting the offending noise. This however may leave you with a disjoint waveform (which would sound like a click itself). To solve this, simply zoom in as soon as you have done the delete without moving the cursor. Then select some samples either side and apply the "Repair". This does not always work - so certainly test this and use the Undo function to go back to where you were before (i.e. undo the Repair and the Delete).

This manual process is very time consuming, but produces excellent results - well worth doing if you have treasured recordings that can no longer be purchased on modern media.

BTW: I also use Audacity mainly for transcribing/repairing vinyl & tapes - and 1.3 has proved well stable enough for these relatively modest needs (you will also get better label handling in 1.3 as an added bonus).

WC