If I were you, I'd see an ENT and have an audiogram.

If is possible that you suffered some pressure-related damage to your middle ear structures. If a problem is found, you could benefit from medical or (less likely) surgical treatment. If the middle ear looks OK, and the audiogram suggests an inner ear problem, the standard of care (at least here in the US) would be to obtain an MRI (typically true for unilateral but not bilateral hearing problems). This would be to rule-out an acoustic neuroma or other tumor.

Tinnitus is subjective, so the best advice after ruling out anything structurally wrong is to try your best to be bothered as little as possible by it. Don't become obsessed.