I agree there is no harm looking for a “fashionable” hearing aid market. What I don’t think the OP is capable of conducting a rigorous methodology to discover if there is a market. I don’t think it is as simple as you laid it out. I don’t think a few prototypes will cut it. I don’t think asking “what do you think” looking at renderings carries enough weight to determine if there is a market. Sure, it is a start and get you to a no quickly, but by no means will it give you a yes. I need to know a shitton more before I go and recommend launching such a product. I even doubt it would persuade management to throw real resources at the “problem”.
Then of course there is my bias. While I have contact with only limited deaf people, I have interviewed hundreds of the disabled. And for that matter, thousands of sick people, the temporarily disabled. And by far, the overwhelming majority do not want their disability to define them. There are always exceptions to the rule, but I don’t know if there are enough exceptions to create a large enough market to commit all of the resources needed to bring a product to market.