Is nerve damage to the ear due to loud noise reversible?

Yes and no! If you are exposed to excessive levels of noise ie a concert you may get a temporary threshold shift ie your hearing ability will reduce temporarily however continued exposure can lead to a permanent reduction in hearing ability. Custom hearing protection if exposed to noise regularly is a must. You have been warned!

As has been noted in the other responses, noise can damage the auditory system.  The amount of hearing loss can vary due to not only the level and duration of the noise, but can be complicated by other factors such as genetics and whether you are a tobacco smoker (higher occurence in smokers than non smokers), or have a medical condition such as diabetes mellitus.  The initial effects of the damage may be subtle and not detected by conventional hearing tests.  Once damage has occurred, since it is both in the inner ear and nerve fibers, we have not been able to correct the problem with medications or surgery.  It is the one hearing disorder which is preventable.  Use of hearing protection devices (whichever are comfortable and effective for the activity engaged), and limiting the amount of time exposed to the high levels of sound will minimize the chance of creating the damage in the first place.  Use of hearing aids is appropriate, or in the case of a profound hearing loss, a cochlear implant should be considered.

The effects of noise damage deoends on duration and frequency of noise exposure along with the intensity of sound. Get an audiogram done to see if there is a  damage to  hearing. PLease assure that you have a quite period ( no exposure to excessive noise ) for at least 24 hours before getting an audiogram . If there is a  noise indiced hearing loss measures must be taken to protect your hearing.. 

Raji Parangad

There are many areas of the inner ear that can be damaged by loud noise, and unfortunately, most of that damage is not reversible.  This is why hearing conservation programs, use of ear plugs, and limiting use of ear buds is so important.  There was a recent article pubslished in Scientific American that explained how noise-induced damage can be observed and measured in the neural fibers even before the microscopic sensory cells (or hair cells) in the cochlea are damaged, and hearing loss could be measured.  (you can read more here at Scientific American)  Unfortunately, the modern world and use of technology exposes delicate inner ears to potentially damaging noise.  It is critical to reduce exposure to noise by using hearing protection, limiting time listening to personal music sources, and advocating for less noise in the enviroment.  

Noise induced hearing loss is not reversible, however some may experience a temporary threshold shift (TTS) after noise exposure, where hearing does return back to prior thresholds after a period of time.  Repeated noise exposure is progressive and permanent.  A general rule of thumb is if you can't have a conversation with someone 3ft away then the noise is at a level to cause damage and hearing protection should be worn.  Noise is everywhere not just occupationally, mowing the yard, concerts, shooting, listening to music with earbuds, football games, chainsaws all can cause hearing loss.

Loud noises damage the auditory nerve over time. Because damage occurs gradually, the cumulative effect of exposure to loud noises may not result in hearing loss until later on in life. As noted by the other responses there are no options to reverse auditory nerve damage in most individuals. This is why it is important for you and loved ones to use hearing protection whenever exposed to loud noises.

What an interesting question! As noted by others, there is no known way to reverse the damage other than what the ear may repair itself. There have been some really interesting studies in our field exploring if there are any chemical compounds in certain medicines or vitamins to help the ear repair itself better afterwards or if there is anything that can be taken beforehand to help prevent worsened damage. The take home message right now remains the same: protect your ears on the front end and that will give you the best result. That said, if you have been somewhere quite loud and have experienced temporary hearing loss as a result, it is best to avoid other loud noise for the next week so that you can get the maximum benefit from whatever repairs the ear can make on itself. Cheers!