Hearing Conservation/Protection

One of most hazardous causes of hearing loss but that is also preventable is noise exposure.  The extent of damage from noise exposure varies depending mainly on the intensity of the noise and duration of the exposure.  The Occupational Safety and Health Administration (OSHA) regulates noise Standard and every work place is required to comply.
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 protector. Investing to protect when they are healthy is much more beneficial than trying to compensate after loss occurs.  The outcome is not comparable.
Get a baseline audiogram and observe annually if you are involved in a very noisy environment either via occupational or recreational.
Get a professional advise and custom hearing protection and educated for better motivation.
Healthy diet and a regular excise also reported as helpful for preserving hearing.
Some of animal studies reported that combination of certain vitamins that are applied before the noise exposure affected the result positively compared to the control group that were exposed to the same noise without vitamin supplement.