Explanation
Each feature and command for SQL Server Audit has individual permission requirements.
Unless otherwise specified, viewing catalog views requires a principal to have one of the following:
* The VIEW SERVER STATE permission.
* The VIEW AUDIT STATE permission (gives only the principal access to the sys.server_audits catalog view).
* Membership in the sysadmin fixed server role.
* The CONTROL SERVER permission.
* The ALTER ANY AUDIT permission.
A principal must have the VIEW SERVER STATE or ALTER ANY AUDIT permission to use the Dynamic Management Views.
References: https://technet.microsoft.com/en-us/library/cc280665(v=sql.105).aspx