I just upgraded to 18.04, and I noticed that the sound from my headphones, whether plugged into front or back port, was very crackling and slow/delayed. This issue didn't exist on 17.04/10. It also doesn't affect audio coming from HDMI via Radeon 560 GPU, just the headphone/onboard audio. The relevant device is:

00:1f.3 Audio device: Intel Corporation Sunrise Point-H HD Audio (rev 31)  

I tried a bunch of fixes for pulseaudio I found googling, including this one and this one. Neither of which helped.

I have found something that at least makes it listenable - changing "default-fragment-size-msec" from 25 to 5 in /etc/pulse/daemon.conf. It makes it much much better, but still a little crackly from time to time.

I've googled for 30 min or more now, and not finding anything else that seems recent and relevant, so wondering if I should maybe open a bug, or if there's something I'm overlooking here.


I had the same issue and killing pulseaudio fixed it for me. I'm not sure why it would get into a bad state, but restarting pulseaudio might be something to try.


killall pulseaudio
  • This is some dark magic. Any idea on what's actually going on? (this works though, I think may be connected to suspend-awake process) – jave.web Jan 7 at 16:55

I had the same problem. It seems related to speech-dispatcher (some text-to-speech utility).
try :

killall speech-dispatcher

If the sound comes back to normal you can remove it completely (if you don't need it) with :

sudo apt-get remove speech-dispatcher
  • 3
    This solved the issue for me on Debian Buster. In my case it was only needed as dependency of orca which I don't use. – lifeofguenter Jun 20 '19 at 17:30
  • Same as lifeofguenter – TheFiddlerWins Jul 18 '19 at 23:19
  • 2
    this fixed it for me, ubuntu 20.04/pop!os 20.04 – Tim Richardson Aug 23 '20 at 6:16
  • 1
    this solved my problem on ubuntu 20.04 – csenga Sep 28 '20 at 14:58
  • 1
    Yup, that was it. The bug would present when my audio output was switching. – ppetraki Jan 29 at 17:13

Press Ctrl+Alt+T to go to a terminal and use your favourite editor to edit the file

nano /etc/pulse/default.pa

then find a line containing:

load-module module-udev-detect

modify this to become:

load-module module-udev-detect tsched=0

save and exit and you're all set!

  • 3
    you need to restart your laptop or run: pulseaudio -k after you change the configuration. – stason Nov 16 '18 at 3:05
  • all it does is makes the sound completely distorted – Display Name Nov 16 '18 at 13:12
  • 1
    This is the solution and it should be the accepted answer -- although it would be good to edit it and add the pulseaudio -k command – Merc Feb 15 '19 at 8:59
  • 4
    An explanation about what exactly this does would be helpful. It can be found at this Ask Ubuntu question – polynomial_donut Jun 4 '19 at 19:09
  • actually, on a newer ubuntu version this actually works. – Display Name Nov 1 '19 at 11:33

I ran into the same issue (crackling sound) today on Ubuntu 18.10 on my Intel NUC Canyon Hades.

killall pulseaudio

only fixed it temporarily for some reason. After a few minutes the problem was back again.

What ultimately did the trick was the answer posted by Fabby in combination with the comment by statson to enter

pulseaudio -k
  • I think when you kill PulseAudio, the OS falls back to ALSA. Most likely your PulseAudio has some configuration issues. – user31389 Dec 15 '19 at 14:17

If you have Firefox or Chrome open when the sound starts distorting. Shut them browsers down and test the sound again. If it has stopped, then you need to use a different web browser. I installed Vivaldi yesterday and I haven't had a problem since. There are many browsers to choose from.

  • Or... Go to about:config in Firefox and search for "media.webspeech.synth.enabled" and set it to "false" (double clicking on the entry should do it) then close Firefox. Open it again and see if that makes audio better. For me it did. – mevdschee Jun 21 at 1:40

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