Treatment for obscure auditory dysfunction (OAD)?

some years back i saw an ENT specialist consultant and he did hearing tests, my results came back normal/maybe slightly above normal hearing. but i have difficulty hearing what people are saying when theres background noise in social situations and also when i work in theatre and theres the background noise of machines and suction (bit of a problem!). i was diagnosed with OAD. he said it was a rare condition and that there was nothing u can do about it. this was some yrs back. was just wondering if anyone knows of any treatment or anything that may help? thanks.