Chemicals can damage various parts of the hearing structures. Earlier, we mentioned that some antibiotics have this unfortunate property, and that certain gene variants make such damage more likely. Some chemicals, such as magnesium, appear to protect the hairs of the inner ear against damage. Smoking has been linked to hearing loss. You probably know that smoking can lead to blockages in the blood vessels of the heart which, in turn, can lead to a heart attack.
Smoking also causes blockages in the tiny blood vessels that nourish the hairs of the inner ear.
If the hairs do not get enough blood, they die or become less resistant to physical damage. A baby whose identical twin has an ear infection has a risk for ear infections that is 6 to 8 times higher than an average child of similar age. Small variations in the anatomy of the ear can make it prone to infections. This appears to be the case in some Native Americans, for example. And small variations in the body's ability to fight infections can also increase the chances of infection.