[Thaeris]

Because of the technical nature of this subject, I'm posting this here and not in Voice Acting. (move if necessary)

Righto, so The E asked me if I'd look into working with a few lines for a project. Because I don't have access to a high quality microphone (just the built-in mic in my computer), I've been using Audacity to enhance audio files. Audacity is a free, open-source program you can obtain from SourceForge of Google.

I've since recorded a track which I've felt is quite good, but there's a significant amount of "popping" in one portion of the segment. I'm wondering what the best way of removing this is; I could get rid of a major "pop" without destroying any real quality, but subtle traces of the crackle remain. Does anyone here know how to do this?

[zookeeper]

Because of the technical nature of this subject, I'm posting this here and not in Voice Acting. (move if necessary)

Righto, so The E asked me if I'd look into working with a few lines for a project. Because I don't have access to a high quality microphone (just the built-in mic in my computer), I've been using Audacity to enhance audio files. Audacity is a free, open-source program you can obtain from SourceForge of Google.

I've since recorded a track which I've felt is quite good, but there's a significant amount of "popping" in one portion of the segment. I'm wondering what the best way of removing this is; I could get rid of a major "pop" without destroying any real quality, but subtle traces of the crackle remain. Does anyone here know how to do this?

The first thing I'd try is simply to see if the traces of crackle are few and far between enough that you could just manually go smoothen them out by zooming in on them and using the pencil tool (my preferred method for fixing very short pops and clicks). If they're so numerous that it'd take forever to do that, I guess I'd try to use a very narrow band-pass filter to filter out the crackle but not much else, but it might not work that well.

Of course Audacity also has a click removal filter built-in in the effects list, but I don't really remember if it was any good.

[Thaeris]

I found the major culprit, which I used the "blank out" function to remove. This had no notable effect on sound quality.

The problem with zooming in and listening to the track is that I've not found a way to slow down the playback, so I can't see what precisely is causing the multiple pops. The beat finder almost seems like it will identify the problem areas, but I've not yet tried the pencil to knock the problems out. Thus, I'll have to try that.

Any other suggestions?

[zookeeper]

I found the major culprit, which I used the "blank out" function to remove. This had no notable effect on sound quality.

The problem with zooming in and listening to the track is that I've not found a way to slow down the playback, so I can't see what precisely is causing the multiple pops.

Well, select the general area, play it (or put it on loop play) and listen if the click is in that area, if yes, then narrow it down a bit, repeat, etc. Still, usually pops and clicks make a pretty visible spike in the waveform, so it shouldn't be too hard to find if you know the general location.

The beat finder almost seems like it will identify the problem areas, but I've not yet tried the pencil to knock the problems out. Thus, I'll have to try that.

Any other suggestions?

Well, not really. If you want, you can post such a file and I can try to clean it up and see what sort of methods I'd end up using in the process.

[Thaeris]

I think I'll do that. Watch your mailbox...

[zookeeper]

I think I'll do that. Watch your mailbox...

Ok, got it. I'll post my reply here in case anyone else happens to find it useful:

This is an example of what I was referring to in terms of a "pop."

The file contains the source .wav file, the .ogg file as well as the audacity project.

I guess you mean the pop at around 1.5s (I just looked at t1.wav, not the project file, since I don't really ever use those myself)...well, here's what I did:

1. Quite obviously it's somewhere in the word "wing", so I just zoomed in there first.

2. The bit of waveform at 1.535 simply looked a bit fatter and rougher than the surroundings, so I figured that's probably the problem area and zoomed in further.

3. At such high zoom levels you usually see a clearly repeating pattern in the waveform, so I just selected the bit which contains the pop - 1.5312-1.5387 - and deleted it.

4. Since I just cut away one "cycle" of the wave, the parts right before and after the popping part still connect with each other nicely, so it doesn't cause any further artifacts in the sound - just like if you have a clean sine wave and cut away one "cycle" of it: the sound stays the same, you just shortened it by a tiny little bit, which no one will notice. Of course, you'll still want to zoom in until you see the individual samples of the "seam" and just smoothen it out with the pencil anyway. Nice, smooth sine-like curves are the way to go in such situations, although if you made sure the begin- and end-points of the selection match nicely to begin with, you usually won't need to use the pencil on but a handful of samples.

That's pretty much what I tend to do when there's a pop or click which is too long to fix by pencil alone.