Issues in Noise-Induced Hearing Loss
With rare exception, noise of sufficient intensity and duration to cause noise-induced hearing loss (NIHL) is essentially a man-made phenomenon (Ohlemiller, 2012). The most prominent cochlear injury (from noise exposure) appears to be damage to the outer hair cells. The number of people at risk for NIHL directly attributable to occupational hearing loss appears to be decreasing (due to hearing conservation programs in the United States) while threats from recreational noise exposure (firearms, concerts, movies, video games, computer games, personal sound systems…) appears to be on the rise. Ohlemiller suggests some 30 million people in the United States are at risk for NIHL. The two most common routes of cell death (secondary to NIHL) are apoptosis (where cells engage enzymes that dismantle DNA, proteins and membranes in more subtle injuries) and necrosis (in which cells "spill" their contents into extracellular space, generally attributable to trauma). Many single and multiple pharmacologic compounds have been tested for their protective ability with regard to NIHL. However, genetic variation and many other individual factors need to be considered and therefore, it "remains to be seen just how effective pharmacologic therapies…can be."
For More Information, References and Recommendations
Ohlemiller KK. (2012) Current Issues in Noise-Induced Hearing Loss. In Translational Perspectives Auditory Neuroscience. Editors: Tremblay KE, Burkard RF. Plural Publishing, pages1-34.