I have some old audio that sounds very good after noise removal, but it has clicks in 3 places. I went back and listened to several versions of this track and even before the noise removal the clicks are there. I’m having a hard time isolating the click in the waveform and deleting it without removing some of the vocals. I tried “click removal” without success. Any suggestions? I’ve attached a piece of the audio that includes one of the clicks. Thanks!
A second clip with the click.
These aren’t clicks and click removal isn’t going to do any good. The click that you get when a phonograph needle runs over a cat hair is a single sharp tick that has a blue waveform signature easily recognized by humans or software. That’s not what you have. You have a produced sound effect like someone playing a drum or a click track sound.
Particularly the second one as you found, the character of the click is too close to the character of the voice to easily separate by filtering, keying or any of the other tricks. I think the only hope is to use a small segment of the existing voice before or after the click and cover up the damaged audio. That’s advanced editing and isn’t easy or fast.
Koz
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use the spectrogram-view to identify the click …
http://wiki.audacityteam.org/wiki/Click_removal_using_the_Spectrogram_view -
then use “repair” or “equalization” to remove the click.
In this case I used equalization as the click only occupied a narrow part of the audio spectrum (2.5KHz-4.5KHz) so could be notched-out.
That’s awesome. But I’m an amateur sound editor. The audacity wiki sure made it look easy to pick out the click, but I’m not seeing the clear-cut spike. You’re also going to have to give me a little more how-to on just what you did to notch out the click in “equalization”
I want to know how you did that, too. I ran Spectrogram and didn’t get any indication of activity at 2.5KHz.
Feature Request note: grid over spectrogram view. Koz
Koz
On closer inspection its lower extent is 2.8KHz rather than 2.5KHz …
I selected the region the click occupies then applied a notch-type equalization …
Slight variations in the selected area can have a big difference on the result,
so a bit of trial and error on the selection is worth a try.
And my colours don’t look anything like that, either. We’ll be looking at that closely later. Koz
I see that and in the same colours that Trebor posts - but it is very hard to spot (but using the ear first and labelling a small range around it helps to home in).
Even Brian Davies’ normally excellent ClickRepair (on its default “Mono” setting) couldn’t catch that click.
Nice work Trebor. 
WC
Maybe your spectrogram is on different settings …
Trebor,
I tried it on my original clip. Worked perfectly!! Thanks so much for the tutorial! I’ll give it a try on the second click and see if I can fix it as well.
Cynthia
The second example is far worse : the noise occupies much more of the sound spectrum, not a limited range of frequencies as in the first example.
Yes, I tried and tried to improve that one without much success. Did you give it a shot? It’s terribly obvious as it is. Even if it were still there, but not quite as loud, it would be an improvement.
Yes , the only alternative technique to notch-type equalization I can suggest is cutting out the worst bit and using “repair” to hide the join …