One of most hazardous causes of hearing loss that is also preventable is noise exposure. The extent of damage from noise exposure varies depending mainly on the intensity of the noise and the duration of the exposure. The Occupational Safety and Health Administration (OSHA) regulates noise standards and every workplace is required to comply.
Noise induced hearing loss (NIHL) also occurs via recreational loud noise such as shooting, power saws, snow mobile, loud music etc. Continuous exposure is more damaging than intermittent. The break between exposures tends to give rest in the auditory system and recovers shifted hearing due to noise.
To reduce the intensity, wear personal hearing protection. Investing to protect your ears when they are healthy is much more beneficial than trying to compensate after a loss occurs.
Get a baseline audiogram and observe annually if you are involved in a very noisy environment either via occupational work or a recreational hobby. Get professional advice and use custom hearing protection.
Healthy diet and regular excise is also reported as being helpful for preserving ones hearing.
Some animal studies reported that a combination of certain vitamins that are taken before noise exposure had affected the result positively, compared to the control group that were exposed to the same noise without vitamin supplements.