Log who opened and view an incident in the audit log

I would like to record who opened and viewed an incident in the audit log.  Currently only changes to a incident are recorded in the audit log.  Our HR department would like to have managers submit a ticket to request salary changes for their direct reports.  Information contained in those types of tickets would be classified as confidential.  Anyone with an administrator rule would have the ability to open and view any ticket(s).  HR would like to have ticket views logged in the audit log.