Someone can also be an audiologist with a Master’s degree. I saw one a few months ago. I do feel that an audiologist knows more about hearing than a hearing instrument specialist. I was referred because I was tested at Costco and they said my word recognition scores had plummeted, and that I should see an ENT. Of course, in our non health system I saw a nurse practitioner. But to stay on topic, I think an HIS can be very useful and knowledgeable about hearing aids, and most of the time they can do what is needed. When it comes to health, even the audiologist can’t do anything.