The Costco where I live is also staffed by hearing instrument specialists (HIS). I know the other Costcos in my city (in Canada), are also staffed by HIS rather than audiologists. The difference between the two is the amount of education they have. HIS usually have a 2-3 year long intense training program. Upon completion, they are able to diagnose and fit hearing aids for adults only. Audiologists, on the other hand, have their doctorate, which, as I understand includes more training to work with people throughout the lifespan, and in particular, children. I’m not sure how it is in the U.S., but in Canada, HIS can only treat adults, whereas audiologists can treat anyone. Plus, as a general rule, audis have more training in diagnosis of hearing disorders (otosclerosis, enlarged vestibular aqueduct, etc.), whereas HIS don’t have training in diagnosis. This is how the differences were described to me by my audiologist, who, until recently, was a HIS.
Is it immaterial? In my opinion, not necessarily. There are really good and really bad hearing instrument specialists and really good and really bad audiologists. (In my short time with hearing aids, I’ve encountered some of each.) There are also really good and really bad nurses, doctors, and lawyers, too. Just as in any other profession, one can have a great deal of knowledge and little to no ability to translate that knowledge into practice. I think as long as you find someone who you can get along with, who actually listens to you, who seems knowledgeable about hearing aids and hearing rehabilitation, and is able to get you hearing to your best ability, then their designation (HIS or Aud.D.) doesn’t matter.
Kerry