Althoughre is still much to be learned about L the relations of hearing loss to noise exposure, we have accumulated enough information through experience and research to enable us to organize and conduct hearing conservation programs. This basic information is, in brief:
Many noise exposures can produce a permanent hearing loss that may affect communication by speech.
Noise-induced hearing loss may be temporary, permanent, or a combination of temporary and permanent.
Permanent noise-induced hearing loss is due to destruction of certain inner ear structures which cannot be replaced or repaired.
The amount of hearing loss produced by a given noise exposure varies from person to person.
Noise-induced hearing loss first affects man's hearing of sounds higher in frequency than those essential for communication by speech. Therefore, most early noise-induced hearing losses pass unnoticed unless they are detected by suitable hearing tests.
Four major factors
Aram Glorig. The Effects of Noise on Man. JAMA. 1966;196(10):839–842. doi:10.1001/jama.1966.03100230083021