[Ger-Poland-Volhynia] German Dialect question

[DLPratt123 at aol.com]

My grandparents surnamed Hirsekorn emigrated from Volhynia in 1906 and  
1907.  The birth certificate for their son (from the Polish Baptist church  in 
Lucinow) is in Cyrillic, spelling the surname in a way that suggests that 
the  s was pronounced like the s in English `vision' or `pleasure'.  Do any of 
 you know of a German dialect in which `Hirse' would have been so  
pronounced?  (This would explain why others occasionally spelled the  surname as 
Hirschkorn.)
 
Dan Pratt