Scid vs PC has limited sound capabilities, It can speak moves in English, or play a tock sound with every move. Alternatively, FICS can also play a tock sound to announce your opponents move.
The feature relies on a slow and poorly maintained Tcl package, Snack, which should be installed by default on Windows and OSX. On Linux this package is known as "libsnack" and "tcl-snack". For more info, see below.
To see if sound is enabled, examine the
Sound may be disabled by selecting an invalid folder.
If Scid only plays every second move, you have a buggy libsnack, and should compile snack-2.2.10 from source.