You can turn off these sound in the Options/sounds.
That's not true, the SFX and Music checkbox doesn't have any effect of some event sounds .. i.e. colonize the first planet, first survey event, etc.
In addition the volume controller has no effect of the "tick" when you click on "Turn" or any other button in the game. It would be nice to have this fixed, as this "tick" is quite annoying. You can set the SFX volume to "0" and this tick is still loud and crisp.
An option to just only disable event sounds and this tick would be highly appreaciated 