pulseaudio does not launch

[Chris J Arges]

When booting my Lenovo T420 laptop, pulseaudio no longer launches at startup. I cannot use volume controls or the gnome sound panel.

I am using raring, 3.7.0-4-generic #12.
$ apt-cache policy pulseaudio
pulseaudio:
  Installed: 1:2.1-0ubuntu4
  Candidate: 1:2.1-0ubuntu4

If I try to launch pulseaudio manually I get the following:
$ pulseaudio
E: [pulseaudio] module.c: Failed to open module "module-esound-protocol-unix": file not found
E: [pulseaudio] main.c: Module load failed.
E: [pulseaudio] main.c: Failed to initialize daemon.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: pulseaudio 1:2.1-0ubuntu4
ProcVersionSignature: Ubuntu 3.7.0-4.12-generic 3.7.0-rc7
Uname: Linux 3.7.0-4-generic x86_64
ApportVersion: 2.6.2-0ubuntu5
Architecture: amd64
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/controlC0', '/dev/snd/hwC0D0', '/dev/snd/hwC0D3', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/pcmC0D3p', '/dev/snd/pcmC0D7p', '/dev/snd/pcmC0D8p', '/dev/snd/controlC29', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
Date: Wed Nov 28 08:14:05 2012
EcryptfsInUse: Yes
InstallationDate: Installed on 2012-08-17 (102 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120807.2)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
SourcePackage: pulseaudio
UpgradeStatus: Upgraded to raring on 2012-11-26 (1 days ago)
dmi.bios.date: 11/28/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 83ET67WW (1.37 )
dmi.board.asset.tag: Not Available
dmi.board.name: 4177CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr83ET67WW(1.37):bd11/28/2011:svnLENOVO:pn4177CTO:pvrThinkPadT420:rvnLENOVO:rn4177CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 4177CTO
dmi.product.version: ThinkPad T420
dmi.sys.vendor: LENOVO