Audacity Forum

When I start and end an audio track, there is a very clear popping noise. I feel like this has happened before and I've gotten around it, but now it is just terrible. I have used Audacity for a long time and never recall running into a situation like this.

I have confirmed it is not my mic. It seems like it may be a computer thing as it happens on the "Sound Recorder" app that comes with Windows.

Windows XP
Audacity 1.2.6


What I don't understand is how this could even happen. This noise is clearly there yet doesn't show up in the sound waves. Export the project to a .WAV and it is again not in the sound waves. I have tried using the noise remover, but it distorts my project greatly when it gets rid of the pops. It also seems silly, because this is still production side. I should be able to take the work I have and fix it at the source rather than just glossing over an export with these pops.

Any help or suggestions are greatly appreciated.

I bet it does show up in the waves. You just need to know what to look for. Almost certainly you have DC offset in your show. If you have clips or segments with that affliction, it's impossible to edit without clicks or pops. This is what it looks like. Note the left wave is slightly lower than the right. The show will pop at the transition.
The solution is to apply Effect > Normalize > Remove DC.

You need to do it to the clips before you start editing. You can't easily fix this in post production -- after you finished editing.

Koz

Oh god bless you lol! Works like a charm!

It is fixed, but I still don't get it. I could sometimes see this wave anomaly of which you spoke, but I could also make a new track without a mic even being plugged in and it still had this problem. If I only generate silence it doesn't happen. Any idea why this is occurring?

Any idea why this is occurring?

Your sound card takes the analog voltages coming from your microphone and translates them into digital signals that the computer understands. It's doing it wrong. And it's not unusual, either. My test picture was taken from a small microphone amplifier I have that has that same error. I own two of them, one of them is broken like that, and the other works fine.

The signals from Audacity are generated by programming inside Audacity. They don't go through the sound card, so they're perfect.

Your sound card is plugged in the computer and working whether you plug the microphone in or not. Windows is set to activate the sound card whenever you choose to use the Line-In, the Mic-In or any of the connections your sound card has. If you buy a USB sound card like a UCA-202...

http://www.behringer.com/EN/Products/UCA202.aspx

It won't have that problem. You're not using the services of your sound card.

Koz