Up to 21 percent of adult-onset hearing loss is noise induced, with 18 percent of adult hearing loss in Africa’s southern-most countries, including South Africa, due to occupational noise exposure. In fact, between 68 and 80 percent of mineworkers are exposed to noise levels of above 85 dB in their daily tasks, comments Dr Dirk Koekemoer, founder and CEO of eMoyo.
Noise induced hearing loss (NIHL) happens when the tiny hair cells in the inner ear are damaged by exposure to excessive noise, reducing their ability to communicate with the brain. Once those hair cells are damaged, they cannot regenerate or be repaired.
“The consequences of NIHL are so much more extensive than difficulty hearing. In a work environment, impaired hearing could result in communication challenges, which in turn could lead to accidents. Hearing loss also leads to social and psychological problems, including everything from shame to difficulty concentrating, and anxiety and irritability to low self-esteem and depression,” Koekemoer says.
These problems are all exacerbated by isolation and trouble communicating. Physical consequences could include headaches and tense muscles, as well as stress and increased blood pressure.
“What’s more, neuroscientists at The University of Texas in Dallas found that prolonged exposure to loud noise adversely affects how the brain processes speech sounds. Put simply – prolonged exposure to loud noise doesn’t just affect your hearing organ, it affects your brain too,” notes Koekemoer.
NIHL happens gradually and workers may not even be aware that their hearing is deteriorating, until they realise that they cannot clearly hear someone who is standing just a metre away from them, or they have difficulty understanding speech after being in a noisy environment.
Other signs include not being able to hear what people are saying or hearing a constant ringing or buzzing noise in the ear, called tinnitus, or feeling a “fullness” in the ears after leaving a noisy area.
“NIHL can be prevented by sound occupational health and safety practices, such as choosing manufacturing or mining equipment that is designed to reduce noise. All industrial equipment should be shipped with noise-related information, and workers should be equipped with hearing-protection devices that have a correlating noise-reduction performance.
“Most importantly, behaviour needs to change. There’s no value at all in being aware of equipment noise ratings and supplying everyone in the environment with top-rated hearing-protection devices, if the devices are not used at all times, without exception,” Koekemoer warns.