In some cases uninstalling Pulse Audio Works, But you should try this first:

1. Open terminal

2. sudo gedit /etc/modprobe.d/alsa-base

3. Add to the end of the file:

options snd-hda-intel model=dell

4. Reboot and then go to the volume control and turned the speaker

volume up to maximum.

And You’re Done.

If it doesn’t work and you want to try to uninstall Pulse Audio Just open terminal and

sudo apt-get purge pulseaudio

You can also go and download The Original ubuntu 9.10 dell factory recovery iso