If the hearing loss is conductive, such as earwax blockage, hearing can usually be restored. If the hearing loss is sensorineural, parts of the inner ear or auditory nerve are damaged. Hearing loss of this type is permanent.

The effects of noise-induced hearing loss may be temporary or permanent, depending on the intensity and duration of the exposure. Ototoxic drugs are medicines that damage the inner ear. Sometimes the damage lasts only as long as you take the drug; other times it is permanent.

Even if you have lost some hearing, it is important to protect the hearing that remains. Unfortunately, a person who has experienced hearing loss might work in a woodshop or other noisy place without hearing protection. This action can lead to further damage to the inner ear.

Source: U.S. National Library of Medicine