Comment 18 for bug 978880

On Ubuntu 12.04 LTS, I solved this issue perfectly on the Vostro 3750 simply by updating to the latest Realtek drivers from

http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=24&PFid=24&Level=4&Conn=3&DownTypeID=3&GetDown=false#High%20Definition%20Audio%20Codecs.

(this page is referenced from https://help.ubuntu.com/community/HdaIntelSoundHowto, scroll to the end).

In my case I had to patch the install script given in the Realtek package (I had version 5.18):

  tar -xvjf LinuxPkg_5.18.tar.bz2
  cd Rt-Linux-HDaudio-5.18/

... then edit file 'install', and change the line

   cd alsa-driver-RTv5.18

into

  cd alsa-driver-RTv5.18/alsa

then run install script:

  sudo ./install

reboot for the changes to take effect (I guess you could try something like "sudo alsa force-reload" instead). Afterwards, plugging / unplugging headset should work flawless. Also these new driver should handle better the bass speaker on the Vostro 3750 (now the bass speaker and speaker volume are sync'ed - in alsa mixer, there is actually no more separate volume for bass speaker, just a toggle to enable / disable it).