no volume level icon due to no audio system running

lsb_release -rd
Description: Ubuntu 14.04 LTS
Release: 14.04

apt-cache policy pulseaudio
pulseaudio:
  Installed: 1:4.0-0ubuntu11
  Candidate: 1:4.0-0ubuntu11
  Version table:
 *** 1:4.0-0ubuntu11 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status

pulseaudio installed but not working
As no system audio running, no volume level icon.
No audio at all, previously, after installing skype it made a highest volume noise which force me to shutdown the laptop and after that I could continue using the computer after mute it.
Next boot I have no sound system running, I did nothing related to configure sound but reinstalling gstream1.0 (sudo apt-get install --reinstall gstream1.0)

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: pulseaudio 1:4.0-0ubuntu11
ProcVersionSignature: Ubuntu 3.13.0-24.47-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/controlC1', '/dev/snd/hwC1D0', '/dev/snd/pcmC1D0c', '/dev/snd/pcmC1D0p', '/dev/snd/controlC0', '/dev/snd/hwC0D0', '/dev/snd/pcmC0D3p', '/dev/snd/pcmC0D7p', '/dev/snd/pcmC0D8p', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CurrentDesktop: Unity
Date: Sat May 10 08:48:56 2014
InstallationDate: Installed on 2014-05-07 (2 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
SourcePackage: pulseaudio
Symptom: audio
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/06/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: X550LC.401
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: X550LC
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: ATN12345678901234567
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrX550LC.401:bd11/06/2013:svnASUSTeKCOMPUTERINC.:pnX550LC:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnX550LC:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
dmi.product.name: X550LC
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.