You can see my hearing loss below, which was taken about 19 months ago. I am writing from my experience only, but seems consistent with what the audiologists’ communicated. I think you will find you are probably missing out on a lot of sounds, and might even be hearing things incorrectly and not know it.
I’ll assume you have sensory hearing loss. Sensory hearing loss means, in short, the person has lost and damaged cells which used to do the hearing. It means there are less cells to pick up and transmit sounds to the brain. Not only does it take more energy (greater decibels) to hear at a given hertz, your ability to make sense of what you are hearing both at that frequency and overall also goes (your brain gets less information), aka clarity.
You will learn, or read sometimes, with high frequency loss you are less likely to hear sounds such as “S”, “v”, “t” and “P”. This is only part of the story, because each speech sound has components across all frequencies. For example, providing there’s no background noise, I can hear “s” and “t” sounds even if someone whispers, about 25 dbs. These are the hardest for me to recognize though in noisy environments.
If you look at a sound meter when someone is speaking, you can see the majority of speech is below 3k Hz. In fact, depending on who you speak with, about 75% or so of speech is below 3k Hz. The other 25% is still needed constantly. It’s because there is sound information there your brain can use, and often needs, to differentiate and recognize most language sounds. More might be there for sounds such as “S”, “V”, etc., but most speech sounds have partial components above 3Hz. Some sounds have a lot more, some a lot less.
The good news is a hearing aid will help provide some of those sounds you are missing, by increasing the sounds to a decibel level you can hear them. They can also help the clarification problem by filtering out and/or adjusting sounds with emphasis where needed. Unfortunately, you still have lost hearing cells, and so hearing aids will have mixed success and can never fully replace lost hearing.