Can one exposure to a loud sound harm your ears forever?

There are three types of noise-related hearing loss. Temporary damage is done slowly and will often come back after a rest from the noise. Often people who have attended a loud rock concert have experienced this type of hearing loss.

Permanent hearing loss occurs over time if the noise/music is loud enough and the exposure time is long enough. The damage sustained is cumulative, so each new exposure can add to hearing loss. Finally, there can be a sudden permanent hearing loss if there is exposure to a brief but very intense sound.