Osten rhymes with:
aasen, bossen, chiasson, claassen, closson, crossan, crosson, fossen, glosson, johson, josten, klaassen, maassen, rosson, rosten, vanfossan, vanfossen, wason
Osten sounds like:
o'steen, octane, ogden, ossetian, osteen, ostin, ostman, oxdon, oxidation, oxidyne, oxton