After heart disease and arthritis, hearing loss is the third most common chronic physical condition in the United States and contributes to significant declines in health and quality of life including cognitive impairment and depression (1). Similar to most chronic diseases that become increasingly visible in our middle years, hearing loss may be significantly impacted by our health behaviors in preceding decades before we understand ourselves to be at risk.
Noise-induced hearing loss is often unrecognized among U.S. adults of all ages. Almost one in four adults who reported good hearing already have measurable hearing loss. According to the World Health Organization, about half of persons aged 12-35 years may be exposed to unsafe sound levels from personal audio devices and at entertainment venues including music and sporting events (2). Noise-induced hearing loss affects 15% of teenagers and 20% of young adults aged 20-29. Also, among people aged ≥18 years, 11 % have tinnitus (i.e., the perception of ringing in the ears or other sounds such as buzzing) and 6% have hyperacusis (sensitivity to everyday sounds) (3,8).
The cumulative effects of hearing damage are more noticeable among older adults. Nearly half of people older than 60 years have hearing loss and 80% of people older than 85 years (4,5). In other words, if you live a long life, you will likely be impacted by hearing loss.
Cognitive Function and Hearing Loss
A World Health Organization metanalysis showed that mild or more severe hearing loss engendered a doubling of the risk for dementia over 17 years. A similar result was seen in a cross-sectional study of 6500 people in the US with a mean age of 60. There was a decrease in cognition for every 10 decibels (dB) of hearing loss even below the clinical threshold of 25 dB. A study evaluating the causal link between hearing loss and dementia included 200 adults with a mean age of 55 and at least 2 brain MRIs. The study followed patients for a mean duration of 19 years and showed a correlation between midlife hearing loss and brain atrophy in the temporal lobe. Of note, hearing aids have been shown to prevent the increased incidence of dementia in patients with hearing loss. A 25-year study of 3800 people over 65 showed increased dementia incidence in people with self-reported hearing loss, except in those using hearing aids (6).
Everyday Environmental Noise Exposure and Hearing Loss
Noise exposure at home and in the community may permanently damage hearing. Sound is measured in units called decibels. According to the World Health Organization, noise levels above 70 decibels can potentially damage hearing. These include loud noises from gardening power tools, sporting events, and headphones. The louder the sound, especially if 85 dB or above, the shorter the amount of time needed to cause hearing loss. In general, the transient noise exposure from the blaring radio of an adjacent car or a slamming door is too short to cause hearing loss. For sounds at 100 dB, OSHA recommends limiting exposure to 15 minutes per day to avoid hearing damage. A single exposure to a 160 dB gunshot can cause instant permanent hearing loss (7).
Aging and exposure to loud noise damage the nerve endings in our inner ear which sends sound signals to the brain. This leads to permanent hearing loss that cannot be corrected through surgery or medicine. Noise-induced hearing loss limits your ability to hear high-frequency sounds and understand speech
Here is a list of common environmental noises and their sound level:
- Threshold of Hearing 0-10 dB
- Normal Conversation 60 dB
- Movie Theatre75-105 dB
- Noisy Restaurant75-85 dB (if you need to raise your voice to be heard by someone 3 feet away, the noise level is likely over 85 decibels)
- Music on Headphones 85-110 dB
- Lawnmower 90 dB
- Slamming Door 90 dB
- Sporting Event or Concert95-110 dB
- Passing motorcycle 95-110 dB
- Crying Baby: 110 dB
- Ambulance Siren 120 dB
- Gas Powered Leaf Blower: 130 dB
- Airplane: 120-140 dB
Strategies To Protect Hearing:
Noise reduction and avoidance may prevent hearing loss or slow its progression. Below are tools that increase your likelihood of maintaining your hearing later in life.
Identify harmful noise. You can easily measure the decibels of sounds in your daily environment with a sound level meter app on your phone (https://decibelpro.app/). The use of technology provides new ways of informing decisions and actions for ourselves and our kids or grandkids.
Simple, protective tools (earplugs or earmuffs) left inaccessible locations can help protect hearing and prevent noise damage from your surrounding environment. Earplugs with a snug fit can provide about 30 dB of hearing protection.
Move as far as possible from the source of loud noise (loud movie speakers or shouting sports fans ). Doubling the distance between yourself and loud noises reduces the exposure by 6 decibels (e.g. moving from 2 to 4 meters from a sound source).
Limit the duration of your exposure to loud sounds. For example, reduce the listening time to high volumes of music.
Purchase quieter household appliances and gardening power tools such as electric versus gas-powered.
Hearing Loss and Healthspan
Hearing loss often progresses for years before being self-perceived or diagnosed. Like most chronic health conditions such as vascular disease where a plaque in vessels can be seen in autopsies of soldiers in their twenties, decrements in hearing begin early in life.
Noise exposure at all ages including younger ages needs particular attention. Cumulative damage from loud noise exposure early in life likely contributes to the high prevalence of hearing loss in our middle and later years. Similarly, loud noise exposure in our middle and later years may accelerate existing hearing loss.
Bradford Rabin MD is a concierge medicine doctor caring for patients in the San Francisco Bay Area including Palo Alto, Menlo Park, Los Altos, Portola Valley, and Woodside.
1 CDC – Loud Noise Can Cause Hearing Loss
https://www.cdc.gov/nceh/hearing_loss/public_health_scientific_info.html
2 Statistics about the Public Health Burden of Noise-Induced Hearing Loss
https://www.cdc.gov/nceh/hearing_loss/public_health_scientific_info.html
3 Vital Signs: Noise-Induced Hearing Loss Among Adults — United States 2011–2012
https://www.cdc.gov/mmwr/volumes/66/wr/mm6605e3.htm
4 President’s Council of Advisors on Science and Technology. Aging America & hearing loss: imperative of improved hearing technology. Washington, DC: Executive office of the President of the United States, 2015. Available from http://hearingloss.org/sites/default/files/docs/PCAST_Hearing_Tech_LetterReport_FINAL.pdf
5 Hearing loss prevalence and risk factors among older adults in the United States
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3074958/
6 Dementia Prevention, Intervention, and care
https://www.thelancet.com/article/S0140-6736(20)30367-6/fulltext
7 Occupational Safety and Health Administration- Occupational Noise Exposure
https://www.osha.gov/noise
8 Survey of Teen Noise Exposure and Efforts to Protect Hearing at School — United States, 2020
9 Noise-Induced Hearing Loss