You would think that reading, television, news programs, documentaries, films, and discussion would be enough. In fact, before I became a volunteer reader, I was sure I could pronounce at least 92.7% of all names I came across.
What I have learned instead is that for every language (Ethiopian, Hebrew, Welsh, German, French, British English, North American English, Dutch, Afrikaans, Middle Eastern…) I look up, pronunciations, even among one’s own lexicon and inter-regions, can vary…widely.
If, on the other hand, you think you can do this in your sleep, you ought to become a volunteer reader (at least). And as a way of testing your ability, try these names/derivatives on for size, and see how many -– and ALL nuances count, because nuances are usually the thing that hold most of us up -- you have right. (I have taken these from the book I am reading now.)
Good luck -– and if you get 98% correct, consider yourself an linguistic genius!
LaPlacian
Joynson (Hicks)
Pigou (Arthur)
Abbabisci (Addis)
Haeckel (E)
Knutsford (Cheshire)
Zuckerman (S)
Piaget (Jean)
Coonoor
Norske
Portmadoc
Tutte (WT)
Ismay (General)
Vernam (Gilbert)
Auchinleck (I nearly fell over when I discovered the Welsh pronunciation)
Michie (Donald)
Zapotek
Irvine (Lyn)
Bernal (JD)
Dedekind (R)
Peano (G)
Frege (G)
Fermat
Beobachter Dienst
Gneisenau
Dunkerque
Winterbotham (FW)
Vannevar (Bush)
Rouse (Ball)
Vignolles
Boughey (CLF)
Mauchly (J)
Lorenz (K)
MacKay (D)
Criccieth
Annan (Noel)
Cribgoch
Womersley (JR)
Mermagen (PHF)
Rajchman (JA)
Zuse (K)
Peierls (R)
Trethowen (Illtyd)
If this helps, I thought I knew 98% of these pronunciations, but I was wrong, wrong, wrong, wrong, wrong!