Note: Single-source report; awaiting corroboration.
Noise-induced hearing loss (NIHL) can occur when sensitive structures in the inner ear are damaged by very loud or prolonged sounds. This type of hearing loss may happen immediately or develop over time, and can be temporary or permanent, affecting one or both ears. People may not notice the damage right away but could later have trouble understanding speech, especially in noisy environments or on the phone.
According to data from 2011-2012, at least 10 million U.S. adults under 70 years old (6%), and possibly as many as 40 million adults (24%), show signs of hearing loss consistent with NIHL. An estimated 17% of teens aged 12 to 19 may also show signs of this condition.
NIHL can result from a single exposure to an intense sound, like an explosion, or from ongoing exposure to loud noise, such as in a woodworking shop. Recreational activities that pose risks include shooting, hunting, snowmobiling, listening to loud music through headphones, playing in bands, and attending loud concerts. Common household noises such as lawnmowers and leaf blowers can also be harmful.
Sound is measured in decibels (dBA). Sounds at or below 70 dBA are generally safe, even with long exposure. However, exposure to 85 dBA or above for extended periods can lead to hearing loss, with risk increasing as loudness rises. Example decibel levels include normal conversation (60-70 dBA), movie theaters (74-104 dBA), motorcycles (80-110 dBA), loud music through headphones and concerts (94-110 dBA), sirens (110-129 dBA), and fireworks shows (140-160 dBA).
Noise-induced hearing loss is preventable. Awareness of noise levels and use of protective measures can reduce the risk.