Restarting didn't solve the problem. Reloading a save did not provide the cure.
I had to log out and reboot the computer in order to get the voices back.
I think I have a handle on what knocked out the voices. It seems to have occured after my anti-virus program popped up with a voice announcement that my virus data base had been updated.
Still a mystery why only voices were silenced and not all sounds.
As a matter of conserving system resources I routinely shut down the anti-virus program while sub-simming. Of course that action doesn't halt the auto update. Doing that whould require constantly going into the program and turning off/on this setting. Another hassel of requiring a permanent active internetconnection to play.
