Some of there are obeseity, welding fumes and exposure to lead and cadmium. Researchers have also found that soft hair on the hair cells in the inner ear means that the sound signals to the brain become weaker and thereby causes reduced hearing.
Lead and cadmium
Low-level exposure to lead and cadmium may contribute to hearing loss. The two common metals, lead and cadmium, which are mostly used in electronics and batteries, may damage hearing, according to an extensive study of several thousand U.S. adults with different degrees of hearing loss.
Adults with the highest levels of lead and cadmium in their body, either alone or together, experienced a drop in their hearing ability of 14-19%.
Continuous exposure to welding fumes increases the risk of hearing loss. As part of their job, many welders are exposed to loud noises, intense heat, blinding light and potentially dangerous welding fumes. Welding fumes have been shown to have a major negative impact on hearing.
Although any type of welding produces fumes, arc welding produces the highest level of fumes.
Obesity in adolescents
Obese adolescents are more likely to develop hearing loss than their non-obese counterparts.
Being obese as a teenager makes you almost twice as likely to develop a low-frequency hearing loss, according to a study from Columbia University's Medical Center. The study revealed that 15.16% of obese adolescents, obese being defined as having a body mass index (BMI) of over 95 percentile, experienced sensorineural hearing loss. In comparison, only 7.89% of non-obese teens suffered from a hearing loss.
Soft hair on hair cells
Previously, it was thought that the hairs on the hair cells were stiff and could only bend to the sides. However, researchers at Karolinska Instituttet in Stockholm have found that the hairs can also become soft.
If the hairs are soft, the electrical impulses become weaker and this means that the sound signals to the brain become weaker.
Soft hairs in the inner ear can therefore be a factor in explaining reduced hearing and age-related hearing loss (presyacusis).