Perceived effects of high frequency hearing loss in a farming population.

Previous research has suggested that farmers are at increased risk for noise-induced hearing loss (NIHL) due to excessive amounts of loud noise exposure from farming equipment. This study was conducted to determine the perceived effects of hearing loss in a small farming population. Ninety-three subjects, ranging in age from 18 to 75 years and actively engaged in the farming industry, were asked to complete a case history form regarding noise exposure and demographic information. Hearing sensitivity was assessed by obtaining air conduction thresholds at audiometric test frequencies 500-8000 Hz bilaterally. Subjects completed the Self Assessment of Communication (SAC) hearing handicap scale if any threshold in either ear was poorer than 25 dB HL. Study results revealed that the presence of high-frequency hearing loss and perceived hearing handicap increased with age, with the largest effects seen in those over 50 years of age. The, relationship between SAC scores and four hearing handicap formulae utilizing different pure-tone averages was also investigated. The highest correlation coefficients occurred for formulae employing higher frequencies and excluding 500 Hz in the calculation. Implications of this study are that audiologists should be aware of the potential hearing handicap associated with high-frequency hearing loss in the farming population and educational programs concerning the dangers of noise and ways to prevent NIHL should be developed for those in farming occupations.