After the latest update in testing, I found sound not to be working. I checked system config in KDE and found the wrong sound card set there. I changed it to the correct sound card, sound now works in some programs and not others (IE, Dragon Player and Amarok have sound, Kaffeine and Iceweasel do not). Sound does not work through the on board sound card.

System beep sounds (through the onboard speaker) also fail to work.

I've had similar problems in the past due to the inability to turn off the onboard sound, alsaconf has always fixed them, however debian has removed alsaconf from alsa-utils.

I disabled the onboard sound in BIOS, Kaffeine now gives a message 'Cannot Create Audio Output' then closes. Sound works in a number of other programs now though.

Settings of kde affect all kde apps since all use phonon as a backend.
Moreover, phonon uses vlc/xine/gstreamer as a backend so as to play its sounds. Do you have any of phonon-backend-* installed?

I have the Xine backen but not the gstreamer or vlc one. Installed those, I now get sound when I log in to KDE, but still no sound in Totem or Iceweasel, and Kaffeine is still giving the error.

Apparently I have no /dev/dsp. I'm not sure why.

Solution:

alsa-oss and oss-compat were uninstalled by the update, reinstalled them, flash is now the only thing with no sound (preexisting problem)