====================================
this method not work

System>Preferences>Startup Applications...

now click add

next name the startup application

Then under command type /usr/bin/pulseaudio
====================================


<fix>

this method work fine for me

Run aplay to list all playback hardware devices:
$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: HDMI [HDA ATI HDMI], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: Generic [HD-Audio Generic], device 0: ALC269VC Analog [ALC269VC Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0

Create/edit asound.conf in the /etc directory
$ sudo nano /etc/asound.conf

pcm.!default{
type plug slave.pcm{
type hw card 1 device 0
}
}

I used card #1 and device 0 (which is the analog sound card) for the system to recognize this card as the default sound card.

Reboot.

$ sudo reboot




source < http://www.ostalks.com/2012/10/27/audio-fix-for-samsung-535u3c-and-lubuntuubuntu/>