Probably has something to do with the available space.
When I go to the audiologist to check up she has to take them into another room to permanently program them with the data chart of my hearing test frequency response. So I don’t know how it’s done..............
“Probably has something to do with the available space.”
Are you kidding? It’s probably no more than a thousand bytes. With the gigabytes you can store on a tiny chip that’s nothing.