No sound in Firefox

[Joseba Llano]

No sound in Firefox. I checked the sound preferences and all is well . The sound if it works in other applications.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: firefox 47.0+build3-0ubuntu0.16.04.1+xenial1 [origin: LP-PPA-gnome3-team-gnome3-staging]
ProcVersionSignature: Ubuntu 4.4.0-24.43-generic 4.4.10
Uname: Linux 4.4.0-24-generic x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: joseba 2370 F.... pulseaudio
 /dev/snd/controlC1: joseba 2370 F.... pulseaudio
BuildID: 20160607113630
Channel: release
CurrentDesktop: GNOME
Date: Sun Jun 26 17:34:14 2016
Extensions: extensions.sqlite corrupt or missing
ForcedLayersAccel: False
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
InstallationDate: Installed on 2016-04-22 (64 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
IpRoute:
 default via 192.168.0.1 dev wlp2s0 proto static metric 600
 169.254.0.0/16 dev wlp2s0 scope link metric 1000
 192.168.0.0/24 dev wlp2s0 proto kernel scope link src 192.168.0.26 metric 600
Locales: extensions.sqlite corrupt or missing
Plugins:
 Shockwave Flash - /usr/lib/adobe-flashplugin/libflashplayer.so (adobe-flashplugin)
 GNOME Shell Integration - /usr/lib/mozilla/plugins/libgnome-shell-browser-plugin.so (gnome-shell)
PrefSources:
 /usr/lib/firefox/defaults/pref/vendor-gre.js
 /usr/lib/firefox/defaults/pref/channel-prefs.js
 prefs.js
Profiles: Profile0 (Default) - LastVersion=47.0/20160607113630 (In use)
RelatedPackageVersions:
 adobe-flashplugin 1:20160616.1-0ubuntu0.16.04.1
 gnome-shell 3.20.2-1ubuntu1~xenial1
RunningIncompatibleAddons: False
SourcePackage: firefox
Themes: extensions.sqlite corrupt or missing
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/21/2014
dmi.bios.vendor: INSYDE Corp.
dmi.bios.version: c
dmi.board.asset.tag: Type2 - Board Asset Tag
dmi.board.name: C16B
dmi.board.vendor: ENZ
dmi.board.version: Type2 - Board Version
dmi.chassis.asset.tag: Chassis Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ENZ
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnINSYDECorp.:bvrc:bd11/21/2014:svnENZ:pnC16B:pvr1.0:rvnENZ:rnC16B:rvrType2-BoardVersion:cvnENZ:ct10:cvrChassisVersion:
dmi.product.name: C16B
dmi.product.version: 1.0
dmi.sys.vendor: ENZ