Mismatches Between Auditory Demands and Capacities in the Industrial Work Environment

Exposure limits to noise in the workplace have been set merely to prevent disabling hearing loss. Consequently, even in workplaces where a limit of 85 dBA-8 h is strictly enforced, the sound environment is very poorly matched to human auditory capabilities. In fact, ergonomists have been led to characterize this feature of the industrial work environment as an 'extreme condition' that is being imposed on a major segment of the workforce. This type of sound environment seriously restricts the possibilities of making use of auditory temporal, spatial, and frequency resolution, and often reduces the latter by damaging the inner ear. Sound warning signals are often too loud or too weak. The temporal features of such signals are frequently distorted by strong reverberation in the local itself. Spatial separation of sound sources is strongly limited by the masking effect of the background noise. The depth of the perceived sound field is generally reduced to very great degree. Workers experience isolation because verbal communication is severely restricted. Most discernable acoustic occurrences are devoid of meaning or are experienced as annoying or irritating. Noise has been reported as the most frequently mentioned factor of annoyance in industrial workplaces. Such environments are far from being matched to human capabilities and are scarcely conducive to work satisfaction. A general remedial framework for making the appropriate improvements is thereby proposed.