If a child suddenly falls behind in class, the reason could be loss of hearing caused by glue ear that can be very easily detected and treated. Hearing problem in elderly people is a different issue where hearing aid is probably the best option. Hearing aid technology is advancing every day with aids smaller and more affordable available to within reach of the common man.
The children who are born deaf or anybody who has lost his hearing suddenly can have their hearing restored with cochlear implant technology, which means a surgery and training by audiologist.
Vast numbers of people suffer from ear infections and related complications. Some of them can be treated easily by eardrops or may be complicated enough to require Mastoid surgery. They may have their hole in the ear drum repaired at the same time or if the infection has destroyed the little bones essential for hearing, they can be synthetically replaced.
People who have dizziness can be due to inner ear problems. Careful examination and advanced testing of the inner ear usually finds the problem.