My husband has wondered why so many men of the United Kingdom seem to have incredibly beautiful voices: Burton, Olivier, Hopkins, of course. Benedict Cumberbatch, to modernize the list a bit. Ronald Colman for fans of old films. Nathan Page, to reach as far as Australia. But, seriously, their voices are, by and large, different from the voices we're used to hearing in America.
Is it because their vocal cords are different, just genetically different? Is it because their schooling routinely allows for rhetoric, elocution, the training of the voice, as a routine aspect of being a gentleman, not merely a quality reserved for the stage? I know that in singing there are exercises to line up one's vocal cords. Perhaps preparation for public speaking does the same thing?
Or for the bar! Go to an English court or Irish court (I can't personally speak for the others), and you will hear magnificent voices worthy of the Royal Shakespeare Company presenting one side or another of a case. These are not the kinds of cases you see in films, with movie actors letting out all the stops to make heart-rending pleas. These are ordinary barristers who are simply trying to win an argument for the prosecution or for the defense. They have incredibly beautiful voices.