This answer got me thinking. If Spock has an unpronounceable name, is this unique to him? We've seen many Vulcans over the years in Star Trek, and I don't recall any of them making mention of them having an unpronounceable (to humans) name. This seems especially odd since it means that Spock's own mother wouldn't be capable of saying his full name.
Do all (or most) Vulcans have names that humans can't pronounce?