Because they do not make things LOUDER; they make them CLEARER.
How can that be, I hear you ask. Because, they only amplify the sounds I cannot hear without them.
Speech to me, without hearing aids, is like someone is talking to me from the next room with the door closed. It is muffled, and hard to understand. I say, "huh?>" a lot. But with the hearing aids, it is as if someone has opened the door. It is clearer.
When you go to buy, the dealer makes an audio-gram of your hearing loss, showing which frequencies are the most affected and by how much. In my case, anything over 4000 cps is Pfft, gone. Say miss or mitt or miff to me, and it is all the same. Ask me to kiss you and I may give you a boot in the ankle, thinking you said kick.
Anyhow, the dealer, a charming lady named Rene, looked at my audiogram and set the hearing aids to amplify the very high frequencies I need, but not the ones I am already hearing normally. Presto-changeo the world becomes clearer.
Now, if you ask me a question and I say "huh?", it is because I was in a dream world of my own. I still walk around dazed, but I hear better.
In case you care, the make is Widex. The model is elan SD-9Me. And they are made in Denmark. Huh?. Denmark, and no, that is not in China.