Unilateral hearing impairment in Oman: a community-based cross-sectional study

This report on unilateral hearing loss is based on the findings of a national survey on hearing loss and blindness in Oman. The survey of randomly selected households was conducted by trained healthcare personnel between Oct. 1, 1996, and Feb. 28, 1997. A total of 11,402 subjects of all ages were screened for hearing loss. Those who reported hearing impairment in either ear were subsequently reexamined by otologists in hospitals to confirm the findings and to determine the cause of the hearing loss. Based on these findings, we calculated that the prevalence of unilateral hearing impairment throughout Oman was 30.06 per 1,000 population (95% confidence interval [CI]: 29.80 to 30.31). Males had a significantly higher rate (36.67/1,000 [95% CI: 34.55 to 38.79]) than females (23.88/1,000 [95% CI: 21.82 to 25.94]). The causes of unilateral hearing loss were different from the reported causes of bilateral hearing loss. Impacted earwax (16.0% of cases) and otitis media with effusion (13.1%) were the most common identifiable causes of unilateral hearing loss; genetic causes were responsible for less than 2% of cases. Just over one-half of the hearing-impaired patients had only a mild hearing loss. Impairment rates varied in different regions of the country.