Occupational deafness is hearing loss caused by specific working conditions. Exposure of a person with normal hearing to intense noise will cause a hearing loss reflected by an elevated threshold of audibility. Noise-induced hearing loss may be of the chronic type if it develops over a period of years, or an acute type if it occurs in a relatively limited time, produced by an acoustic stimulus which is intense but of short duration. In either instance, noise-induced hearing loss is an irreversible and incurable disease which can only be corrected to a small degree by hearing aids. If severe enough, it can cause permanent work loss, and severely limits a person's ability to function effectively even in normal daily activities.