Work-related or occupational hearing loss is an illness that is affecting a substantial percentage of the population. According to the Centers for Disease Control and Prevention (CDC), work-related exposures cause about 24% of working people’s hearing problems. Loss of hearing causes a significant decrease in the quality of life considering the importance of this sense in interpersonal communication and professional life.
The working environment can cause hearing loss in multiple ways. Although long-term exposure to loud noises in the background causes most of the work-related hearing losses, even being exposed momentarily to loud noise - for example, an explosion - can cause permanent damage to the ear.
There are small receptor cells inside the human ear (inside the snail-shaped cochlea more specifically) that move and flutter with the incoming noise. They transform this movement into electric signals, which are then transmitted to our brain via nerve fibers, letting us consciously perceive what is happening around us and what is being told. Although what these cells are doing is miraculous, they are fragile and susceptible to damage. Any sound above 85 decibels (dB) causes these cells to malfunction, and if the exposure is long enough, it can cause permanent damage.
85 dB roughly corresponds to the noise of a truck that is passing by within a short distance. Although this noise does not seem unbearable, there are work environments such as factories that constantly have noise at and over this level. When a person first steps into such an environment, the initial feeling is discomfort. After a while, adaptive mechanisms against loud noise within the ear and brain activate, and one starts to feel less uncomfortable. Think of the last time that you were at a concert. Although the person feels less disturbed as time passes, the sound is still the same, and the damage is still happening! Certain workers are exposed to it 10 hours every day for years. It might be easy for them to ignore this minor nuisance and keep working. The bad news is with this long and constant damage, the harmful effects start to build up on cells, and permanent hearing loss happens. Even short exposures to high-intensity sounds, such as in rock concerts or night clubs might cause minor permanent damages.
Unfortunately, it does not always take years for the damage to be permanent. If the noise intensity is above 150 dB, even seconds would be enough. That could happen if an explosion occurs at a close distance. Gunshot noise can also have that effect if close enough to the ear. With these types of injuries – called acoustic trauma – there is also the possibility of eardrum perforation and mechanical damage to the ear’s tiny bones. That would manifest as bleeding from the ear. If such trauma would happen, it is crucial to immediately seek medical care since sometimes the damage could be reversible with early intervention.
Luckily, some solutions could quickly apply by everyone working in such environments. The most important step is avoiding noisy areas as much as possible. As a rule of thumb, if you have to shout to communicate, the noise in that area is too much and might cause hearing loss. If exposure is unavoidable due to the nature of the work, protective equipment should be worn at all times. Thanks to the latest technology, it is now possible to use ear protection that lets human conversation pass through but block dangerous sounds. It is important to follow local work safety guidelines about the areas that pose risks to hearing. Finally, for people continually working in noisy environments, it is essential to have a hearing test every six months or at least every year to diagnose any hearing loss as early as possible to prevent further damage.