In our previous post, we discussed how hearing can be harmed by noise and loud sounds. To keep it simple, the louder a sound or noise is, the shorter the time you want to be exposed to it and the further away you should be. Here are 3 general rules for protecting your hearing from harmful noises: These 3 rules might just save your hearing.
- The louder a sound is, the shorter amount of time you can safely be around it without permanently damaging your hearing. So if a noise or environment is loud (chainsaw, concert, music, equipment, etc.), limit your exposure time!
- The more distance you can put between your ear and a loud noise the better. Get further away from a speaker at a concert. Don’t use power equipment close to your head/ears. Maintain a safe distance from machinery.
- When in doubt, use hearing protection. Cheap, foam earplugs, when installed properly, decrease sound pressure levels 15-20-dB. That is enough to protect your hearing from most any noise, at least for a short term exposure.
Some potentially harmful noises are obvious to even the most casual observer:
- Loud concerts
- Heavy machinery
However, there are a number of dangerous sounds to which we are regularly exposed that you might have never considered.
No, I don’t mean standing outside on a windy day. I mean air turbulence caused by rapid airflow past your ear. This can happen with motorcycles, jet skis, boats, snowmobiles, even driving long distances with the window down in a car or truck.
A study of noise and motorcycle riders showed potential for both temporary and permanent hearing loss due to wind noise. High speed wind creates turbulence across the opening of the ear canal. The higher the speed, the louder the noise can get. Scientists have measured wind turbulence in the ear canal to produce noise in excess of 105-dB.
2. Orchestral Music and Marching Bands
When I take a case history from patients, most of them admit to having attended some rock concerts where they left with their ears ringing. Ringing in the ears or tinnitus, can be a sign of hearing damage.
Tinnitus experiences for a short period of time is likely due to what is called a Temporary Threshold Shift (TTS). A TTS occurs after exposure to loud sound due to metabolic exhaustion of the nerve endings (hair cells) in the inner ear.
Most people would expect that after a rock concert, but likely not in a high school band or symphony orchestra. However, depending on the distance from the instrument, noise levels in excess of 106-dB have been recorded from symphonic orchestras. High school, college, and competition bands—especially percussion sections—may produce sound levels ranging from 100-108-dB. Indoor practice sessions can be especially loud due to reverberation of sound.
3. Hair Dryers
While most of us don’t spend hours with a hair dryer on a daily basis, sound levels from hair dryers have been measured at 95+dB. According to the OSHA Noise Standard, 95 dB is permissible for short periods of time, but prolonged exposure could potentially be detrimental.
Remember the inverse square law we discussed in the last blog? Halving the distance from a noise source makes a sound four times more intense, so the sound of a hair dryer really close to the user’s ear could definitely be harmful.
4. Gas-Powered Weed-eater/Grass Trimmer
I spent several summers during college working on a mowing crew, and many hours running a gas-powered string trimmer. Trimmers are moderately loud, about 90-dB at a normal operational distance. However, just like the previous discussion with the hair dryer, the closer the sound is to the ear, the exponentially louder it gets.
When using a weed eater for edging, it is common practice to turn the trimmer vertical so that the engine is very close to the head. This allows professional lawn guys to make those beautiful straight edges where grass meets sidewalks or driveways. Unfortunately, the sound level is now 4 to 8 times louder and the risk for hearing loss is much greater.
My patients regularly ask me about earbud or headphone use and the potential for hearing damage. Just like everything else with loud sound, moderation is the key. When I was a teenager, if you wanted to listen to music with headphones, you had carry a bulking tape cassette or CD “Walkman.” At best, you had about one hours’ worth of music before you had to change a cassette or CD.
Of course today, almost all of us carry smartphones with music. I could cue up my music on my phone and listen for 24+ hours without ever repeating the same song. The problem is one of convenience. It is so easy to listen through earbuds or headphones for long periods of time. As long as the levels are moderate (85dB or lower) that is not a problem; however, listening at a high level for long periods of time can definitely cause hearing damage.
The key with headphones or earbuds is shorter periods of time and moderate levels. If the person next to you can hear your music blaring from your earphones, it’s probably too loud.