...especially with the use of a smart phone app...
Based on my observations of my father's struggles with various hearing aids, hearing aid smartphone apps are just as terrible as any other apps developed by hardware manufacturers. Don't expect the "clinicians" to help with this aspect either, because they were trained on a previous version of a different app and how could they be expected to figure out the apps that are used now?
What's really needed is a decoupling of the hearing test from the calibration activity. A basic hearing test takes a few minutes in an isolated box with headphones (the 'ol click a button if you hear the tone test). From that profile it should be trivial to build out the profile of what frequencies to boost and what not to and program the aids there.
I appreciate the optimism (and do think there's some room for efficiency improvements!), but each step is a little more complicated than that. a true audiometric room/booth to do the testing (eg fully soundproof) in is very rarely found outside of audiologist offices or specialized academic spaces, for starters, and I do believe those are required for paperwork (whether it be insurance related part of the process to getting the right device fitted).
then there's also additional complications like types of hearing loss impacting calibration - some people react very negatively to higher (or lower) frequencies than others do, to the point facial stimulation can happen, and some people just have a frankly tricky profile that requires a trained audiologist on hand to work with them through several sessions, if not outright yearly on top of that, since the nerves and brain output can change by itself.
(source: have a cochlear implant, been doing the described experience since I was ~ 3yrs old.)
To add to this — I suffer from Ménière's disease, which manifests for me as variable hearing loss. Some days are bad, and I can hardly hear/understand speech even when someone is right in front of me and I can lip-read. Some days are good, and my hearing aids are uncomfortably loud or make things sound "weird". But most days, my hearing aids do exactly what I need them to :-)
I've had audiograms taken on moderate and bad days, and the difference in frequency response was significant (up to 30dBA difference across only the lower frequency bands).
my partners hearing aids has a smart phone app, but it seems to be built with the concept of someone else putting the calibration into it. They can then create profiles for the different situations, however it strikes me that the hearing test calibration could be done in the app as well. I would imagine for a lot of people, if you could just buy them online you wouldn't need the clinicians for many cases.
The app for my hearing aids allows my audiologist to make remote adjustments, so I don't even need to visit their office for straightforward changes. I really want to reverse-engineer it so that I can modify some of the details of the profiles myself.
I have many ideas about how the industry can be improved, especially with the use of a smart phone app and user interactions.
Not only is it plausible, but would make the clinicians (fitter) job easier and lead to far more hearing aid sales.