The ears should be kept clean. If washed sufficiently often, and syringed once a week with warm milk and water, or with very weak soap-suds, gently warmed, the cerumen or ear wax will hardly be found accumulated in such masses as to produce deafness.
W. Allcott,The Young Mother - Management of Children in Regard to Health. Amazon
Conductive hearing losses usually involve abnormalities of the middle and external ear, and generally have a mechanical cause (eg, perforated eardrum, fluid in the middle ear, disarticulations of the ossicular chain, cerumen accumulation).
Summary, referring to B. Yueh et al - J. Am. Med. Assoc. 2003 289:1976, ScienceWeek, Vol. 7 - Number 21B, May 23, 2003. ScienceWeek
Cerumen is the medical name for the yellowish, brownish waxy secretion produced by the sweat glands in the external ear canal.
Earwax - the medical name is cerumen - is a normal protective substance secreted by glands near the outer end of the ear canal, the passage between the part of the ear you can see and the eardrum, where the middle ear begins. It moisturizes and protects the delicate tissue that lines the outer ear canal. Its role is similar to that of mucus in the nasal passage and tears on the surface of the eye.
Many people produce more wax (cerumen) with increasing age which, if it is soft, naturally makes its way out of the ear canal. If its thickness increases however, it dries and hardens to block the canal and impair hearing.
Dr Sarah Brewer, Telegraph, 3 October 2000. Telegraph