Popping in the audio. ( Surprise it's not the mic)

So after two days of getting pissed off and about to file a ticket to get my mic checked out and repaired i decided to one more test.

This test had me go back to the video the same time the poping shows up in my audacity line up.
Help please.PNG
To my surprise the poping is not in the original .mp4 file recorded by OBS. After doing some more digging my only conclusion is it is audacity. This is futher proven that i made a OBS recorded muted the mic ( Blue yeti) And the spikes where still in the audio even when there is no audio.

I have lost many videos to this noise that ive been able to slightly fix through leveling it all out but i would like to know what is causeing this problem to avoid it in the future.

Also since i can’t find the edit

Mic is a Blue Yeti

OS is Windows 10

2.1.2 is my audacity

And i want to say it was the .exe installer

Does the problem still happen if you record with the project rate (lower left corner of the main Audacity window) set to 44100?

It does not as far as i can tell however i would prefer not to have to use audacity dureing my recordings since OBS recording are done with the streams done over OBS.

I’m also posting another picture. The Tracks in order are 1.mixed 2.Mic 3. game audio

What strikes me as odd is in the mix of both the game and mic audi there is only 1 spike where the mic audio has 9 ( not counting the far right one that matchs as that was a sneeze)
Odd very odd.PNG

Here’s another of a different video no spikes in 1.track one ( Game and mic ) But plenty of spikes in Track 2. ( Mic ) And no Spikes in Track 3. (Game)

Are you trying to record with OBS and Audacity at the same time?
What exactly are you trying to do? What’s your set-up? How do I replicate your set-up so that I can replicate the problem?

No Both my Audio and Video is recorded in OBS through a 1-3 track system 1. mixed 2. mic 3. Game. I then Import the audio int audacity for editing and cleanup. However in the past few weeks it’s been adding those spikes in there even when their not in the .mp4 file when i go to that same timestamp.

All i’m wanting to do is to find out why audacity is adding audio spikes that don’t exist into the files and how to prevent it without haveing to edit them out every single time.

The punctuation is ambiguous, but I think you’re saying that you record everything via OBS, and that produces a .mp4 file which you import into Audacity for editing. Have I understood correctly?

I think I know what’s happening.

Digital audio data (“PCM” audio) is just a series of number. Each number represents the amplitude of the waveform at a specific point in time on a specific audio track. Normally these numbers are in the range -1 to +1. In special cases, sample value may be greater than 1, or less than -1, but they must always be numbers.

Inside the computer, numbers are represented as a sequence of “on” and “off” states. This is the computer’s binary representation, called “bits”. Some sequences of “bits” represent numbers, so represent characters, some sequences don’t represent anything.

When dealing with numeric values, there are three types of “special” values that can cause problems. “Infinity”, “negative infinity” and “NaN”. These values should never occur in valid audio because they are not “valid” numbers. I suspect that the imported .mp4 file contains occasional “corrupted” sample values that are not valid numbers, and that it is those invalid numbers that are producing the clicks.

To test this theory. Zoom in close on the start of the click and select a tiny bit of audio starting just before the click and ending just after the click. The selection should be less than 100 samples. Then use the “Sample Data Export” tool (http://manual.audacityteam.org/man/sample_data_export.html) to export the sample values to a text file. Set the “Measurement scale” to “linear”. Then open the exported text file and look carefully down the list of numbers. I’m expecting that at the start of the click there is an infinite, negative infinite, or NaN value.

It does not seem to be what you suggested i did a few more then 100 samples due to the spike not being 1 big spike ( picture below ) along with the .txt.

All 4 High areas seem to be the spike i hear on the audio.
sample-data.txt (5.92 KB)

I can confirm that this is an audacity issue. In the attached file i have Audacity and then another audio program. Only Audacity is showing the spike. As mentioned before you can’t hear the spike on the mp4 before i import it into audacity so it’s not something that is there by default.
Oh boy.PNG

In your image, why does only the middle track of the three called “Aoeo part 1” have a spike? Were those other imports from another copy of the file?

Which is the other audio application? It’s OK to give the name, as we are asking.

Please upload the MP4 to DropBox or your favourite cloud server and give us the URL to download the file. Please tell us the exact times in the file where you can hear or see a pop.

Also please clarify if this is correct or not:


  1. There are three tracks from top to bottom in order. 1. Mixed 2. Mic and 3. Desktop. Not sure why the Mic audio has spikes when the Mixed Audio is both the mic and desktop.

  2. The other audio app was Mixpad

  3. I’ll upload the mp4 but as ive said before you can’t hear it in the recording from the times on the audacity timeline

  4. Yes that is correct. OBS records my video/audio the audio is the three separate tracks as mentioned above.

https://www.4shared.com/rar/2OhdTZWWca/Test_needed.html is the audio i wont upload the video unless needed

44 seconds is first spike

2:54 is the second

5:19 is the third

8:55 is the Fourth

24:42 is the Fifth

1:38:18 is the sixth and final one

Could you upload the sample somewhere that does not require logging in, thanks. There’s some suggested methods here: https://forum.audacityteam.org/t/how-to-post-an-audio-sample/29851/1

Sure i can do that heres the .wav

Also another thing that just came to my attention on this fine Monday afternoon. My Setup during these issues was (-.- ( Desktop / Mic /Desktop )) anyway i sat down this afternoon after coming home from work and the computer was off (Therefore no sound whatsoever) any way i’m siting here doing nothing when i hear this clicking sound that after investigation appeared to be coming from the top left corner of my right desktop screen. I am not 100% sure if this is the issue i am experiencing but i will move my setup to .-- to get the mic away from both screens. (However i do live in Alaska so it is entirely possible my screen is poping due to expanding a contracting in the cold/warm temps we get on a normal day in the current season it can get as low as 25 on a night and a high as 78 during the day. The room my PC sits in is temperature controlled however only by an AC/heating unit as we lack central heating up here to keep the house a cousey all around temperature. ) I’ll do a test with my new setup to see if the poping presist in my audio and if not i will assume it was the clicking from the screen.

Thanks. I doubt that the popping in the recording are due to thermal effects as these pops are clear patterns of numeric data.

It could still be due to an effect of invalid data, but by the time it has been converted to WAV it has become “real” data. What I need to do now is to look at one of your mp4 files that does not pop until imported into Audacity.

Right now, everything is pointing at occasional bad data in the mp4 file. If Audacity is the only program that has problems with the MP4, then it could be a bug in Audacity.
What other players have you tried playing the MP4 with? I’m betting that it’s not just an Audacity issue.
It may be possible to workaround the problem by converting the MP4 to WAV with another program and then import the WAV into Audacity, but my guess is that any FFmpeg based converter will have the same problem.