JYOTI TEWARI,CANADA,17 August : Most people experience occasional ringing(or roaring,hissing,buzzing,or tinkling)in their ears.The sound usually lasts only a few minutes.If it becomes persistent,you may have tinnitus.Tinnitus is often the result of damage to the nerves in the inner ear,usually caused by prolonged exposure to loud noise.Other causes include excess ear wax ,ear infection ,dental problems,head injuriesand medications, especially antibiotics and large amounts of aspirin.Excessive alcohol or caffeine intake can also cause tinnitus or make existing tinnitus worse.In rare cases ,tinnitus can be caused by a brain tumour.