Hello,

I am on Scientific Linux release 6.7 (Carbon) and am trying to embed 
sound in a beamer presentation.  The beamer multimedia package defines a 
control sequence \sound for the purpose.  When I use it,
the resulting pdf displays a button to click and the file contains a 
line
/Subtype /Link /A << /S /Sound /Sound 12 0 R /Mix false /Repeat false >>

However none of xpdf, evince or acroread will play the specified sound 
file when the button is clicked.  The acroread error message says 
"Cannot find an appropriate player for the sound", and the less 
immediately interpretable messages from xpdf and evince presumably come 
down to the same thing. The system has the "play" command from sox as 
the default for audio/x-wav files, specified via /etc/mime.types and 
/etc/mailcap, and running

xdg-open file.wav

from the command line plays the file.  So the pdf viewers are evidently 
not consulting /etc/mime.types and /etc/mailcap.  Does anyone know where 
they do look for a sound player?

Stephen Isard