Rivenoak,
I have a few more web sites for you in case you are interested!
Here's one that shows the category of hearing losses:
Degree of Hearing Loss
Audiologists average the results of the audiogram taken at 500, 1000 and 2000 Hz. They take that average and use the chart to categorize people's hearing loss. Personally, I disagree with this approach. The higher frequencies are very important also, and I don't understand why they are left out. I think it gives a very incomplete picture. But I always try to understand the language that the other folks in the room are using, and this is the language and definition that not only the audiologists and ENTs use, but the government does also.
Anyway, using that approach, your son would probably be categorized as having a mild hearing loss. But I think that overstates his hearing a great deal, because it doesn't reflect how much his hearing drops above 2000 Hz. In the higher frequencies, he's not getting a lot of sound, obviously.
I think its good to be aware of this categorization system. You may find it necc. to occasionally remind others of its shortcomings and how it actually can fall very short in describing a hearing loss.
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This chart shows common sounds overlaid over an audiogram. Obviously the creators of the chart must be taking the averages of common sounds -- but IMHO, it's still helpful.
Dayton Ear, Nose & Throat Surgeons, Inc. - Doctor's Hearing Service
You can see that its likely that your son may hear many speech sounds with his right ear, unassisted with HAs. Because he hears lower pitched sounds better than higher pitched sounds, he probably more easily understands men's speech than women's or other children's speech.
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BTW, I think you and your son could use some additional info from his audi i f you don't have it already. Do you know his word discrimination rate? Did the audiologist give your son that test? Often people with hearing loss located in the inner ear have a better chance of having poorer word discrimination compared to people who have hearing loss located in the middle ear. The poorer your word discrimination the more it means that sound is not being processed well in the inner ear and its getting scrambled. The lower one's word discrimination scores they less likely one can understand amplified speech well. But even for people with poor word discrimination, amplification can be helpful. It can help with speechreading (aka lip-reading) and it helps keep you aware of trucks, cars and other important things happening nearby.
I see brackets on your son's audiogram. I believe that may be your audiologist marking the results of his combined right and left ears bone conduction test.
You may want to ask her to test his ears separately with masked bone conduction tests if she hasn't done so already.
In the lower frequencies your son gets better results in the bone conduction test than in the air conduction tests (circles (right ear) and xs (left ear)). That means that a lot of his hearing loss in the lower frequencies are due to a condition in his middle ear rather than in his inner ear.
You may want to ask your son's ENT what condition your son has in his middle ear that is causing those results. It's possible that could give you valuable information for now and the future.
I would ask around and see if you can find someone that has a mixed loss like your son. I don't know what its like to get amplified sound where the loss is due to a middle ear condition and there's very little hearing loss in the inner ears -- and as mentioned, that appears to be the case for your son in the lower frequencies. That might be good information to have.
And have you ever listened to an audio simulating hearing loss? There are some web sites that have that.