this game appears to be mostly silent, but from the starting location, if I go to the left transporter pad(?) then walk up to the computer thing and use it, I can hear beeps and bloops when scrolling through the menus there.
No special command line switch, though apparently we have different versions of the game.

I have two versions. one which i can start with the command "star.exe" and the one from the Silmarils collection which was put out recently, which starts with the command "start.exe"

Generally Silmarils games start with that god awful long beep noise at their logo. I was surprised not to hear that.

My copy is a "star.exe" one. So you don't get any sound in either version? I don't hear the godawful beep, but there's sound once I get to the point mentioned above.
This game uses the PC speaker for sound, btw, in case you're setting anything strange in the config or mixer. And it's rather quiet (had to turn it up to hear it clearly, myself).