hello and welcome to HCM,
Your son is all thirty ears and of course very conscious about his appearance and in spite of that if he has agreed to wear a hearing aid
then i guess you can consider the other option that is surgery:
1. The surgery to otosclerosis
is a simple, safe and a relatively minor surgery which if successful can give your son an almost normal hearing right on the table!
2. The surgery is performed always on the worst ear that is the ear having more loss so your better ear is not touched!!
3. In a worse case scenario where the statistics rule then only the worse ear is lost and you still have the better ear and since you have already agreed to wear the hearing aid, it will not be a change from the original plan! But this type of failure is very rare.
I would thus advice you to undergo the surgery as the results are very good in experienced hands
Dr Sriram Nathan