Audio pop when pressing play


Before I decided to post here I searched the forums and Google, trying to find existing forum posts regarding this matter. However, I found none. Now, this might be an indicator that I’m either using the wrong terms, or that very few experience this … or that many experience this but few regard it as a problem.

Anyway, the thing is this:

Whenever I press play (clicking the corresponding button or pressing space bar) Audacity first gives a little “pop” sound. This sound is the same type of “pop” as you hear when a sound is cut through a non-zero crossing (though a little softer). This happens even if the sound begins at an amplitude of 0. After it has made it’s pop I can playback without these pops (as long as I’m not in the middle of a non-zero crossing point) but after a while, when playback has been stopped for half a minute or so, Audacity makes this popping sound again (by itself, without any user interaction), and the next time you press play, you will hear the pop before the audio starts playing.

Now, the following is just speculation but, it kind of feels as if the pop sound comes from Audacity communicating with the sound driver and turning on/off the ability to make sound. Again, just speculation!

Any experiences on this?

Also, not the same issue really but not entirely unrelated; Audacity also makes a popping sound whenever starting/stopping playback in the middle of an audio track (which isn’t strange at all considering it’s probably due to a non-zero crossing point) - is it possible to make Audacity do a small fade (by just a couple of milliseconds) whenever starting/stopping playback?

I’m very thankful for any input!

MacBook Pro 13" (Early 2011)
OS X 10.6.8 (Snow Leopard)
Audacity 2.0.5

Start with a fresh Audacity and Generate > Silence for any duration. Does that pop when you play and stop?

Import or open a short sound track that does this and apply Normalize, but only select [X] Remove DC. Does the track pop?

If you get noises for both of those tests than yes, something in your system is causes the pops. The majority of start and stop pops is caused by DC offset in the show and it doesn’t have to be particularly visible on the timeline, either.


Just reading through that again, if Audacity makes popping sounds by itself, you could be in feedback.
Audacity > Preferences > Recording: Deselect the top three settings > OK.

How are you listening? In detail. Built-in speakers?

Thanks for the tips! When I generated silence I couldn’t hear any pops. Then I generated a tone, waited for a while and I could hear a small pop when I pressed play. After that, I tried the normalization with everything except Remove DC Offset and that seems to get rid of the pop!

I have unchecked the recording options you mentioned as well, since recording is something I never use Audacity for.

I’m listening through speakers connected to the built-in input of my MacBook.

What I meant to write was of course “output”, not “input”. But then, on my macbook they’re the same :slight_smile:

Yes. If you have a 13", they used one connection and switched it in Preferences. I have a 15" and I have two, intentionally bought that way.


Might Macbooks turn off the audio subsystem after 20 seconds of inactivity be anything to do with this?

Does Audacity 2.0.3 or 2.0.2 do it ( Google Code Archive - Long-term storage for Google Code Project Hosting. )? Quit 2.0.5 (Audacity > Quit Audacity) before trying other versions.