Meeting Han-Wen last time I asked him how the name `Nieuwenhuizen'
actually does sound. To make it short: I'll stay with `Jan' and
`Han-Wen'.
I'll take a stab at it, though I'm no expert at this kind of thing (the
words nine, when, and zen are the American English pronunciations): :-)
Nienhuys --> nine - hyoos
Nieuwenhuizen --> nee - oo - when - hoo - zen
Note that there are no accent marks given; my best guess is that they
would fall on the second to last syllable in each case. This is also
most likely the wrong pronunciation in any case.
So how did I do? Did I get anywhere close? :-)