NF2 and Vestibular schwannoma: Secondly, the etiologies for which an ABI is indicated are quite diverse, and include individuals with congenital hearing loss of genetic origin (who are often children), those with acquired hearing loss due to cochlear nerve disruption from head trauma, those with NF2-associated tumors (typically vestibular schwannoma), those with non NF2-associated tumors, and those with severe cochlear ossification.