Occupational noise and demographic factors in hearing

Abstract

Lutman ME, Spencer HS. Occupational noise and demographic factors in hearing. Acta Otolaryngol (Stockh) 1991; Suppl. 476: 74—84.

The effects of age, sex, socioeconomic background and noise exposure on hearing were examined in a population sample. Subjects, aged between 17 and 80 years, were selected from the electoral register using a stratified random sampling technique based on age and reported hearing difficulty. Exposure to occupational, social and gunfire noises was estimated retrospectively from a structured interview. Analysis of the audiograms of 2 162 subjects free from any material conductive impairment led to a simple model requiring only first—order factors of age, occupational group (manual or non—manual) and occupational noise exposure, but with parameters different for the two sexes. These models accounted for up to 58% of the variance in hearing threshold level (HTL), depending on frequency. It was not possible to separate out gunfire noise exposure as a factor because of a confounding effect of age. For females there was no significant effect of noise exposure, possibly owing to small numbers of noise—exposed females. The dependence of HTL on age agreed well with published literature, particularly for males. For males, noise exposure was associated with a modest increase in HTL, mainly between 3 and 6 kHz. The model was consistent with reported HTLs for males with equivalent noise exposure.

Key Words:

• aging
• presbycusis
• sex
• socioeconomic group
• noise—induced hearing loss