People generally wait ten years after they first get signs of hearing loss before they seek medical help. In that time, some pitches which are fading get lost forever and even hearing aids won’t bring them back. The earlier people get aids, the more chance they have of experiencing proper hearing both then and as they age. Hearing aids can be really hard to get used to and you need to persevere, wearing them all the time, until you adapt to them. They often need tweaking until they work. They can be exhausting. They’re hard for elderly people to manage for the first time - fiddly and easily lost, difficult to insert if you have arthritis and hard to change tiny batteries if you aren’t used to them.
For goodness sake, get him to have his ears tested. It might not be that but I bet in lots of these cases it is a vain man who hates the idea of needing hearing aids which for some reason people are so snotty about compared to needing specs. You really don’t know unless he has those ears tested.
Women are harder to hear in most hearing losses.
You can hear better when you concentrate harder when you have a hearing loss but it’s so tiring - at home you are more likely to switch off and then it appears selective.
People, specially men, can get all arrogant and haughty as a defence mechanism. Become rude rather than admit that part of their body is not functioning as well as it did.
I’ve seen it so many times.