Question: Can I get a hearing aid without anyone at my home knowing about it?
Answer: Well that will be up to you and whether or not you can keep from shouting praises about them. Your question sounds much like the story of a man who had hearing loss and didn’t tell his family he had new hearing aids. He went home, heard their discussion about him and changed his will three times.
Seriously, if your concern is the appearance of a hearing aid, I can assure you that asking others to repeat and/or answering inappropriately will be far more noticeable than something tucked behind or in your ear. It is not uncommon that in a short time, your quality of life will be so improved you will decide cosmetics are a nonissue.