Drop Outs

Audacity Help Forum Windows
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Hey All,

What are Drop Outs? While recording, a second track appears below with the words Drop Outs just below certain parts of the recording track. When I play my recording back, it blips where the drop outs are listed on the second track. It happens at some point, and often several times, during a recording when I’m editing using punch and roll. Any ideas on how to stop this from happening?

Thanks,
Donna

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Drop-outs are gaps or “glitches” in the recording where the recording process was interrupted. It’s related to multitasking.

Here are a few troubleshooting tips.

…Actually, the multitasking operating system is constantly multitasking & interrupting even if you’re only running one application. The audio data flows-into a buffer (like a long pipe or holding tank) at a smooth-constant rate. When the operating system gets-around to it, the data is read in a quick burst and written to the hard drive.

If some application, process, or driver hogs the system for a few milliseconds too long, you get buffer overflow and a glitch in your audio. It doesn’t have to be using lots of CPU time, it just has to hog it a little too long.

There is also a playback buffer that works the opposite way. It gets filled in a quick burst and the audio data flows-out at a smooth-constant rate. In this case the danger is buffer underflow if it doesn’t get re-filled in time.

Note that both buffers introduce latency (delay). That’s not a problem for recording and playback but it can be a problem if you are monitoring yourself with headphones.

1 Like
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Hey Donna! Did you ever find a fix for this? This is the exact thing happening to me all of a sudden!

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There is a FREE online book about optimizing your computer for audio called Glitch Free.

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I never did resolve it. It still does it occasionally. :roll_eyes:

I just read DVDDougs response, above your post, and his last comment says it doesn’t affect the actual recording, just what we hear in the headphones?? I had no idea that was the case. I always go back and re-record the section but now not so sure that’s necessary, if I’m reading his comment correctly??

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I would like to point out my comment here in this forum from September 23: Audio dropouts on playback - #16 by henrymy
There I described obviously the same problem.
I appreciate the exlanation above from DVDdoug and also the link to “Glitch free” document. I will study it in detail later. The browsing of the document didn’t show me a solution.
Here my main point why I think its an Audacity problem:

  • The problem arises when I updated Audacity from 3.0.0 to 3.3.3. I know that Audacity changed the internal file handling at that time

  • I can measure the drop out time in a length between 30 ms and 300 ms. The method for this measurement I described in my Audacity-link above. Anybody may imagine how long this time is in relation to operating system time slices.

  • In the meantime I updated Audacity to V3.4.2 and I can see nearly the same dropout behaviour.

If I could find a solution in the Glitch-Free document I’ll let you know this.