Is it a frequent problem with autism? Do you also experience that? My hearing is so bad that I had a medical assessment done and the medical staff said it's because of an attention deficit, because there is nothing wrong with the hardware, but I can't pick up words when there is background noise. I was offered a training program but I refused, because behavioral therapy has harmful effects for me. I'm already being careful with so many things that I'm paranoid. It's exhausting.
Very interesting question. It's something I have pondered asking.
I was born with a hearing defect. After considerable testing, I was diagnosed with a totally deaf left ear. But, I always knew that was not true. Finally, I explained to the audiologist that my left ear cannot be deaf, because I can hear in stereo. Finally, I got an audiologist that says that the testing issue is that the equipment is only made for testing traditional hearing loss. It is not accurate in all cases especially with non-traditional issues.
In any event, it has been found that my issue is neurological. That is still physical, but physical in the brain, not my ears. My left ear works only when the signal received matches in both ears. If it is too far out of phase or too large a level difference then it doesn't "hear" anything. However, it works fine for stereo imaging. I can tell where a sound is coming from. When the audiologist keeps turning up the left ear volume, when it reaches a particularly high volume, I still can't hear it, but it gives me vertigo so sever that I loose my balance.
I too, cannot understand anyone if there is any extraneous sounds when they speak. Especially if it is another person speaking. Forget about conversation in a crowd of people with many talking at once. If more than one person is talking at the same time, even if it is just two and only one is close to me, it sounds like they are speaking a foreign language. Total gibberish.
Personally, I don't think any sort of training could help. I have been this way all my life and I'm in my 70's. I also doubt that therapy can "fix" physical neurological circuits in the brain.
I'm so used to it that I figure it's just a thing. Not a great detriment, just an inconvenience. But, I'm with you; I feel that therapy would be harmful. Just my opinion.