The hearing impairment is noticeable only when it is substantial enough to interfere with routine activities. At this stage, a permanent and irreversible hearing damage has occurred. Noise-induced hearing damage cannot be cured by medical treatment and worsens as noise exposure continues. When noise exposure stops, the person does not regain the lost hearing sensitivity. Noise-induced hearing loss occurs randomly in exposed persons.
Some individuals are more susceptible to noise-induced hearing loss than others.
Hearing sensitivity declines as people become older. This medical condition is called presbycusis. Again, just like noise-induced hearing loss, everyone is not affected equally. Hearing ability may continue to worsen even after a person stops work in a noisy environment. Certain medications and diseases may also cause damage to the inner ear resulting in hearing loss as well.