I think there's some confusion here. Oracle Database Vault is not an auditing product, it's an access control product, and restricts access to an Oracle database based on several criteria. Oracle Audit Vault, on the other hand, is the auditing product.
To better understand how to deploy Oracle Audit Vault, I recommend you read the Audit Vault Administrator's Guide, and the Audit Vault Auditor's Guide. Both can be found on OTN.