Siaha
Siaha is the head of one of the families of Nethinim — temple servants — among those who returned from Babylonian exile under Zerubbabel. The parallel list in Nehemiah preserves the name in the slightly shorter form Sia.
In the Ezra register
The roster of returning Nethinim names "the sons of Keros, the sons of Siaha, the sons of Padon" (Ezr 2:44). Siaha appears in a sequence of family-names without further detail; the umbrella collects only the entry itself.
The Nehemiah parallel
The same register, redrawn in Nehemiah's account, reads "the sons of Keros, the sons of Sia, the sons of Padon" (Ne 7:47). The shortened form Sia stands in the same position as Siaha in Ezra, identifying the two as one family.