Criteria for managing audiometric data in occupational hearing conservation

Abstract

Hearing conservation programmes usually include hearing testing, although it is not always clear whether the aim of such testing is to identify individuals with a hearing disability, or those who show evidence of having been affected by noise. The requirements for hearing testing in both cases relate to three main considerations: the choice of frequencies at which hearing is assessed; the way in which this threshold data is quantified or otherwise managed; and whether this index is compared to some static limit, or to the individual's own baseline audiogram to assess hearing change. Central to the assessment of hearing for the purpose of identifying individuals at risk for noise-induced hearing loss is a measure that is both sensitive and specific to the effects of noise. A case is made for a choice of frequencies around 4000 Hz, the substitution of hearing loss configuration for the three-frequency average, and an emphasis on hearing change rather than status as a means of interpreting audiometric data for hearing conservation purposes.