For typical long term exposure to high level sound that results in permanent hearing loss, a cascade of chemical events occurs when the cell is metabolically “overloaded” and the cell undergoes a process known as “apoptosis.” The cell that is damaged beyond its ability to recover literally fragments and the pieces of the cell are ejected into the fluid of the cochlea. Cells around the now missing hair cell serve as “scar tissue” to maintain the structural integrity of the system, but these supporting cells do not contribute to the active process of hearing. This damage results in sensorineural hearing loss and, often, tinnitus.
In 3 days, 9693 web surveys were completed. Hearing loss was defined on a Likert scale as "a very big problem" by 8% of respondents compared with other health issues: sexually transmitted diseases, 50%; alcohol/drug use, 47%; depression, 44%; smoking, 45%; nutrition and weight issues, 31%; and acne, 18%. Notably, most respondents had experienced tinnitus or hearing impairment attending concerts (61%) and clubs (43%). Only 14% of respondents had used earplugs; however, many could be motivated to try ear protection if they were aware of the potential for permanent hearing loss (66%) or were advised by a medical professional (59%).
As previously mentioned, a hearing protector can give an average of 30 dB noise reduction if worn continuously during an 8-hour workday. If taken off for just one hour while exposed to noise, however, such a protector would provide only an average of 9 dB of protection during the 8 hours. This substantial reduction in protection occurs because with the logarithmic scale used to measure decibels, a 10-times increase in noise energy occurs for each 10 dB increase in sound. Thus, during the hour with unprotected ears, the worker is exposed to 1,000 times more sound energy than if earplugs or muffs had been worn. (For the 30 dB, 10 x 10 x 10 = 1000 times more noise.)