Hearing Loss & Prevention: An Overview

How Hearing Damage Occurs

Sounds of less than 80 dB, even after long exposure, are unlikely to cause hearing loss. It is impossible to predict how individuals respond to loud noises – each person’s sensitivity to sound is different. However, we know that exposure to a one-time-only or continuous noise can cause temporary hearing loss. If hearing recovers, this temporary loss is called temporary threshold shift, which typically disappears 16 to 48 hours after exposure.

Hearing loss can also be permanent if loud sounds damage or destroy the delicate ear cells in your inner ear called cilia. Once these cells are damaged or destroyed, they cannot be repaired. Research into regenerating inner ear cells is underway but has not yet advanced to the treatment stage.

Noise-Induced Hearing Loss (NIHL)

For many people, tinnitus is a symptom of hearing loss. More than 90 percent of American Tinnitus Association members with tinnitus also report some hearing loss. For many, loss is at the higher frequencies, which is often induced by exposure to loud noise.

Noise-induced hearing loss can be caused by a one-time exposure to a loud sound or by repeated exposure to sounds over an extended period of time. Healthy hearing habits can help prevent hearing loss and tinnitus. However, the effects of loud noises can worsen existing tinnitus and further degrade hearing. If you already have one or both of these conditions, protect your ears from further damage. If you do not have them, learn how to protect your hearing (see below).

What Does "Loud" Mean?

The loudness of sound is measured in decibels (dB). Most experts recommend that you use earplugs when exposed to 85 dB and above. But what does 85 dB mean? The following list shows common sounds and their associated sound levels.

20 dB - Ticking watch
30 dB - Quiet whisper
40 dB - Refrigerator hum
50 dB - Rainfall
60 dB - Sewing machine
70 dB - Washing machine
80 dB - Alarm clock (two feet away)
85 dB - Average traffic
95 dB - MRI
100 dB - Blow dryer, subway train
105 dB - Power mower, chainsaw
110 dB - Screaming child
120 dB - Rock concert, thunderclap
130 dB - Jackhammer, jet plane (100 feet away)

Hearing Conservation Tips

Hearing conservation means protecting your ears from excessively loud sounds:

• Walk away from loud noises.
• Turn down the volume.
• Limit the intensity of the noise by not standing directly near its source.
• Limit the time you expose your ears to loud noises.
• Wear earplugs when you’re around sounds of 85 dB and above.
• Turn down your CD/MP3 player or car stereo system.
• Cross the street when you hear someone operating a leaf blower.
• Wear earplugs at concerts/go to the back of the nightclub or outside to give your ears a break.
• Cover your ears with your hands when you’re walking past a jackhammer.

Good Resources

• Use the NIOSH Noise Meter to hear the different sounds and sound intensities of everyday objects: CDC.gov/niosh/topics/noise/noisemeter.html
• Check out DangerousDecibels.org, a great website for kids and adults alike, that tests your knowledge of noise risk and just how loud sounds in our everyday lives can be.
• To see what other patients have reported about hearing loss and tinnitus, check out the Tinnitus Data Archive, Tinnitusarchive.org, for statistical summaries of tinnitus patients.
• In addition, PubMed, Pubmed.org, is a great public resource for easily searching a library of medical studies. Search the site using relevant keywords such as “hearing loss and tinnitus.”