Lack of audit trail in oracle database

Observation:

Lack of audit trail in oracle database

Audit logging over database is not enabled.

Absence of recording of important events in the systems increases the risk that unauthorized system actions, such as deleting or modifying sensitive data, access attempts and configuration changes may not be identified and resolved in a timely manner.

Question :

Our Auditors raised the above observation therefore to invoke observation i tried to check on which level Audit is on and I found that Audit Logging is enabled at somewhere (Standard Audit Trail) like Database users Sucess and Failed Attempts found by running (select * from SYS.AUD$; ) but i want to track down