When the microscopic structures are damaged, there is no way to repair them to restore reasonable hearing. Typically, hair cells are damaged or destroyed when their supporting structures are overworked. With continued exposure to high-level noise, the membrane motion is great and the cells that support the hair cells swell. Eventually, they rupture and the hair is destroyed or damaged. Only a few hair cells may be lost at a time, but with repeated exposure over days, months and years, the cumulative effect can be substantial.
Intensity is the loudness of a sound, or the pressure it exerts through the ear.
Sound intensity levels. The normal range of hearing begins at approximately 0 decibels, a level at which a person with excellent hearing is able to detect a sound. The dBA rating is provided for many pieces of agricultural equipment. The higher the dBA number, the greater the risk of damage to hearing. The higher the number, the higher the frequency.