Noise is any unwanted sound. In the workplace, there are three different types of noise we are concerned with: continuous, intermittent, and impact. Long-term exposure to noise or sudden exposure to noise can result in noise-induced hearing loss. This type of hearing loss is caused by damage to the hair cells in the ear, causing the “hair” to break off or the cell to die (NIDCD, 2017). Once this has occurred, those broken hairs and dead cells are no longer able to detect sound.

When exposed to noise, there are three types of noise-induced hearing loss that a worker may experience:

1. Acoustic trauma – exposure to an impact noise or physical trauma to the inner workings of the ear
2. Temporary threshold shift – temporary hearing loss, with enough time between exposure hearing is regained.
3. Permanent threshold shift – permanent hearing loss due to long-term exposure to a high sound level and inadequate recovery periods in between.

In occupational health, noise-induced hearing loss is the most common work-related disease (WorkSafeBC, 2018). Hearing loss can have a dramatic impact on an individual’s life. It can lead to a reduced ability to perceive acoustical warning signals, difficulty localizing sound sources, and difficulty with verbal communication. This can lead to stigmatization, reduced social participation, and reduced autonomy. Hearing loss causes stress and frustration for the worker and their coworkers, families, and friends.

Noise induced hearing loss is permanent and irreversible. While hearing aids may be used to help improve the quality of life of an individual, they will never gain back their full hearing. Hearing aids can’t fix broken or dead cells. This is why it is imperative to focus on prevention using the hierarchy of controls: elimination or substitution, engineering controls, administrative controls, and personal protective equipment.