Damaged Hair Cells = Hearing Loss
"Hearing loss is the third most common chronic health condition in the US. Almost twice as many people report hearing loss as report diabetes or cancer. Noise exposure away from your job can damage your hearing just as much as working in a noisy place. Being around too much loud noise—like using a leaf blower or going to loud concerts—can cause permanent hearing loss. And once it’s gone, you can’t get it back! You can have hearing loss before you even notice you’re having problems. Noise is measured in what are called decibels (dB). Over time, listening to loud sounds at high dB levels can cause hearing loss. Sound vibrates the eardrum and tiny bones in the ear which in turn vibrate the hair cells in the inner ear. Exposure to loud noises over time can permanently damage the hair cells, causing hearing loss. The louder a sound is, and the longer you are exposed to it, the more likely it will damage your hearing. The more often you are exposed to loud sounds over time, the more damage occurs."
Source: 2017, Feb. 21). Too Loud! For Too Long! https://www.cdc.gov/vitalsigns/hearingloss/index.html.