I've been familiar with "Neanderthal" since I was a small boy, pronounced and spelled with the soft 'th'....I've decided to be stubborn and stick with the old...

I'm right beside you Whitman!
And if someone is so sassy as to tell me "It's pronounced Neandertal"
I shall wither them with a glance!
(It's a talent all High Priestesses must master.)
Aloha,
wow
ps : The mighty Enigma corrects Neandertal to Neanderthal. Vindication!