My sound has recently stopped functioning.  This seems to be all sound,
Youtube on Firefox and Xine are both silent.

I am using Pulseaudio.


marc@quixote:~$ dpkg -l | grep pulse
ii  apulse:amd64 0.1.13-2                                amd64       
PulseAudio emulation for ALSA
ii  libpulse-mainloop-glib0:amd64
16.1+dfsg1-2+b1                         amd64        PulseAudio client
libraries (glib support)
ii  libpulse0:amd64 16.1+dfsg1-2+b1                         amd64       
PulseAudio client libraries
ii  libpulsedsp:amd64 16.1+dfsg1-2+b1                        
amd64        PulseAudio OSS pre-load library
ii  libsox-fmt-pulse:amd64 14.4.2+git20190427-3.5                 
amd64        SoX PulseAudio format I/O library
ii  pulseaudio 16.1+dfsg1-2+b1                         amd64       
PulseAudio sound server
ii  pulseaudio-utils 16.1+dfsg1-2+b1                        
amd64        Command line tools for the PulseAudio sound server


If I run pavucontrol and have a video running on Youtube in Firefox, or
on Xine, then it shows the fluctuating sound on the 'Playback' tab, but
no sound is audible.

I just noticed something that seems pertinent.  In pavucontrol, on the
'Output Devices' tab, the port is listed as 'Line Out (plugged in)"
which is correct, but the slider below that is almost all the way to
'Silent' at -64.00 decibels.  This would seem to be the issue, but it is
disabled, so that I can not set it higher.

Does anyone have any ideas what might have gone wrong, and what I can do
to fix it?  Or what I can look for the further narrow down the problem?

I did, recently, allow aptitude to uninstall a lot of packages,
including libraries, that is claimed where automatically installed, but
unused.  I would guess that one, or more of these libraries was actually
in use, but not knowing the inner workings of pulseaudio I have no idea
which might be involved.  I did make a copy of the list before allowing
aptitude to uninstall them all.

Marc