What is Noise-Induced Hearing Loss?

Noise-Induced Hearing Loss, or NIHL, happens when you listen to loud sounds. These sounds can last a long time, like listening to a concert, or they can be short, like from gunfire. Three factors put you at risk for NIHL:

• How loud the noise is
• How close you are to the noise
• How long you hear the noise

Sound-level meters measure noise levels. We record noise levels in decibels, or dBA. The higher the noise level, the louder the noise. You can listen to sounds at 70 dBA or lower for as long as you want. Sounds at 85 dBA can lead to hearing loss if you listen to them for more than 8 hours at a time.

Sounds over 85 dBa can damage your hearing faster. The safe listening time is cut in half for every 3-dB rise in noise levels over 85 dBA. For example, you can listen to sounds at 85 dBA for up to 8 hours. If the sound goes up to 88 dBA, it is safe to listen to those same sounds for 4 hours. And if the sound goes up to 91 dBA, your safe listening time is down to 2 hours.

The World Health Organization and International Telecommunication Union 2019 document, WHO-ITU Global Standard on Safe Listening Devices and Systems [PDF], recommends that manufacturers equip devices like smartphones and personal audio players with information that explains safe listening (for adults, a total of 40 hours of weekly exposure to volume levels no higher than 80 dB is recommended; for children, the level is 75 dB); usage warnings and tracking information; cues for taking safe listening actions; options for limiting volume levels; and volume limiters expressly for parents to use. The recommendations would also have safe listening information appear on external product packaging and advertising, as well as on manufacturers’ websites.

Citations

• World Health Organization, WHO-ITU global standard for safe listening devices and systems, 2019. Retrieved from https://www.who.int/deafness/make-listening-safe/standard-for-safe-listening/en/. 
• U.S. Environmental Protection Agency, Office of Noise Abatement and Control. (1974, March). Information on levels of environmental noise requisite to protect public health and welfare with an adequate margin of safety  Retrieved from https://nepis.epa.gov/Exe/ZyPDF.cgi/2000L3LN.PDF?Dockey=2000L3LN.PDF [PDF]