A work up by an ent with an audiogram would be a good first step. As discussed earlier, loud noise exposure can lead to hearing loss and tinnitus. Making sure that there is no conductive component (difficulty with transmission of the sound to the inner ear) will also be evaluated. If there are differences in hearing between each ear, further work up with imaging or more specialized audiological tests (ABR) might be indicated. Good luck.
He should see an otologist--an ENT who SPECIALIZES in the ear. Ask his primary care doctor for a referral, or see the lists at the American Neurotology Society Web site.
First off, he needs a formal hearing test. The ENT will order that. If there are sinus issues, the ENT can check into that as well.
High-frequency hearing loss with age is normal, but he sounds too young to be experiencing the degree of it you describe. Ringing in the ears (tinnitus) is also common, but again, it's not exactly normal.
Both of these things can be caused by too much exposure to loud noise, such as rock concerts. I hope he always uses earplugs!! If not, he'd better start!! Once your hearing is gone, it doesn't come back, and tinnitus usually doesn't go away either.
That said, I hope the doctor finds a treatable cause for his problems.
As your daughters grow up, don't allow them to expose their ears to excessive noise with their future iPods and concerts, etc. Young people are damaging their hearing en masse, but they won't realize it (and won't care) until it's too late. Earplugs always at concerts. Keep the music player turned down. See this great educational Web site:
Best of luck,