A build-up of earwax can cause dulled hearing and sometimes other symptoms. Earwax can usually be easily removed. Earwax is a build-up of dead cells, hair, foreign material such as dust, and cerumen. Cerumen is the natural wax produced by glands in the ear. It forms a protective coating of the skin in the ear canal. Small amounts are made all the time. Flakes or crusts of earwax break off and fall out of the ear from time to time.