My Mac has started flashing the screen instead of beeping. It's exactly the same effect as you'd get if the Accessibility pref pane's "flash the screen" option was enabled, except that it's not enabled.

Accessibility settings pane

I also verified that the preferences property list file affecting this setting shows it as being off. In ~/Library/Preferences/com.apple.universalaccess.plist I see:


In case it makes any difference, the system sound is otherwise normal and not muted. I'm listening to music from iTunes, but getting screen flashes instead of beeps.

This happened a couple of weeks ago, and rebooting the Mac got things back to normal. Why does it keep happening? Is there something I can do to stop it from repeating again? The screen flash is going to give me a seizure.

  • This is a weird suggestion so I'm not posting as an answer, but try resetting the PRAM. Feb 22, 2013 at 21:04
  • 1
    Somehow, after all these years - same problem started to me after upgrade to macOS BigSur 11.4 (20F71), sadly killall coreaudiod didn't help...
    – Jarek
    Jun 14, 2021 at 17:31

3 Answers 3


In a similar situation, I was about to give up and reboot, but then I found that restarting the audio daemon resolves the issue:

sudo killall coreaudiod

The symptom was: in the "Sound Effects" system setting panel, selecting alert sounds didn't do anything (usually it triggers a preview of the selected effect). My guess is that OS X fails to play an alert sound, and falls back to the visual cue.


in case your problem still persists: I could solve it by opening the universal access plist file you mentioned in your post with xcode and deleting the flashScreen entry. after a reboot it behaved as it should. If you don't have xcode installed maybe deleting the plist file may help.

cheers, quam


I had the same thing happen - the setting in Accessibility->Audio is turned off, but the screen flashes anyway.

I wonder if it has something to do with using LogMeIn. It has a long-standing bug of not switching your audio output/input device back to the built-in speaker/mic after a remote session closes. During the session, sound is routed through a special "device" that transmits the sound in/out to the machine controlling the computer. When the session ends, it should revert the audio in/out device back to what it was before the session, but usually fails to do that. The bug has been reported to LogMeIn for years, but apparently they don't plan to fix it, and won't respond on the bug reports.

That's why I wonder if this could be a related issue, although I hadn't seen it happen before today. Did everyone else with this issue also have LogMeIn?

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