Efficiency vs. acceptability of hearing protectors in industrial environments

Abstract

Although hearing protectors must be used as a temporary solution, their choice should take into account several aspects, such as ergonomics features associated with this kind of device. The present study aims to analyse the relationship between the acoustical attenuation efficiency and other aspects related to the comfort afforded by hearing protectors, and consequently their acceptability, when used in industrial noisy environments. A comfort evaluation was performed using a questionnaire, filled by 20 workers. Several scales related to the subjective feeling of comfort were used to quantify the comfort index of a given protector. Simultaneously, the wearing time of each protector was self-recorded by each subject. To test the relationship between the comfort index and the time during which protectors were used, it was applied a variance analysis (ANOVA). Results obtained seem to demonstrate there are significant differences between catalogued and effective attenuation. Protectors with less catalogued attenuation, but with higher acceptability, i.e., more comfortable, tend to be more efficient than protectors with higher catalogued attenuation, but less comfortable. Finally, it must be emphasised that high efficiency can only be achieved through the attainment of an adequate balance between the range of parameters likely to determine its usage.