Do GPs have to sign-off audiometric test results?

To be as unambiguous as possible on this - there is no requirement that all screening hearing tests and reports have to be ‘signed off’ by a doctor.

If someone is identified in their screening test as having a problem then they should be referred to a medical professional, and in all likelihood, in the first instance it will be a doctor. I am guessing that this is where the HSE Inspector is muddling things up - referrals should be via a doctor, which is the normal way screening hearing tests work, but a doctor does not have to sign off all workplace audiometric tests and reports.