Ear Pathology: Its Role in Hearing Impairment

摘要

In a steelworks study of manual employees aged 55–64 years, 31 (20 per cent) of the 152 men had a history of ear pathology (disease or injury, other than noise-induced). The median hearing level (mean readings½, 1 and 2 kHz, right ear) of those with ear pathology was 28·2 dB and for men without a history of pathology 20·3 dB. These data, taken in conjunction with Robinson's figures, suggest that the average man of 60 years of age with ear pathology will have his hearing as much or more impaired by this pathological process as by 40 years of full-time employment, without ear protection, at a sound level of 97 dB(A). In 331 men aged 45–54 years, pathology again played an important part in hearing loss, with a median hearing level 6·7 dB greater than the median for those without pathology.The proportion of men with mild or marked impairment (American Academy of Ophthalmology and Otolaryngology (AAOO) criteria) was 6 times greater in the group with a history of ear pathology than in those free of pathology.Some aspects of audiometric policies in industry are discussed. The need for further discussion is emphasized; this discussion should precede any governmental policy for industry in