For pronunciation of "eu" and "e" in "Eule," see
(A) " 'au', 'äu' and 'eu' " for the former (the former (as in "braun") pronounced brown; the latter two pronounced "oi," which explains German noun feminine Europa Europe; derived from Greek Europa, a Phoenician princess in Greek mythology) and
(B) "Unstressed '-e' and '-er' " (sounds like "a" in English noun "sofa").
(iii) German English dictionary:
* Orgelbau (noun masculine): "organ building, organ making" http://dict.tu-chemnitz.de/dings ... elbau&iservice=
^ Orgel (noun feminine): "organ" https://en.wiktionary.org/wiki/Orgel
^ Bau (noun masculine): "building" http://dict.tu-chemnitz.de/dings ... y=bau&iservice=
黑尔维希 Hellwig is a German surname.
(A) The German and Dutch surnames Helwig/Hellwig are "from the medieval personal name Heilwig, Helwig (female and male), composed of the Germanic elements heil luck + wig war."
(B) For pronunciation of "g" at the end of a word, see (a)(ii).