Can Earphones Damage our Hearing?

You see it everyday and everywhere. People jogging or while doing their work out. People on their way to work or even those in long journeys. The introduction of portable music players has led people to using more and more earpieces so other people can’t hear what they’re listening to. Some do it, not just to enjoy music, but also to block out ambient noises on buses, trains or just the street.

Few people probably realize, though, that listening through earphones at high volume for just an hour everyday is dangerous. It can damage their hearing. A recent study by scientists in Europe concluded that playing and listening to loud music every day for five years could cause permanent and irreversible hearing problems. Five years seems like a long time, but using ear phones would have the same effects at a much shorter time.

How many have been affected?

Estimates put the number of people at risk in Europe at between 2.5 and 10 million who could suffer from hearing loss from listening to MP3 players at unsafe volumes, and the number of people in other parts of the world where portable players are used widely aren’t included yet.

In the US, around 5 million teenagers aged between 5 and 20 have some form of hearing impairment caused by exposure to noise. Ten million people in the U.S have noise-related hearing loss and twenty two million workers are exposed to potentially.   From 13 million in 1970 (pre-mp3 players), the number of children affected has reached  over 30 million today. Children who use personal music players are particularly at risk because their hearing is acutely sensitive.

How is hearing damaged? 

Sound travels to the ear canal and causes the eardrum to vibrate. Inside the middle ear, a bone attached to the eardrum vibrates and propagates sound waves through the middle ear by way of two other ear bones, which amplify the sound. The third ear bone vibrates against the cochlea of the inner ear. The cochlea is filled with fluid and is lined with frequency-sensitive hair cells that convert vibrations into electrical signals going to the brain and loud music can damage  hair cells. Over time, the hair cells can become permanently damaged and no longer work, producing hearing loss. 

With loud speakers, sounds travel several feet before reaching the listener’s ears. By the time they arrive, a portion of the high frequencies have been absorbed by the air. Low frequencies are not absorbed as much, but they are more felt through bone conduction than actually heard.

With headphones, the ears hear all frequencies without any attenuation, because the transducers are literally pressed against them. Thus, when listening to headphones at the same effective volume level as loudspeakers, headphones may still transmit louder high frequencies that are more likely to cause hearing damage. Using earphones can also induce infection in the ears because when plugged to the ear canal, they create a warm, moist environment in which bacteria can thrive.

Earbuds pose more damage because they are placed directly in the ear and can boost the sound signal by as much as six to nine decibels.

When should you see a doctor?

Hearing damage can a gradual and cumulative process and it is without obvious warning signs. The only way to diagnose it is though a hearing test and a medical damage. But once you start having the following symptoms, it is best to consult with an ear doctor – ringing or buzzing in the ears, difficulty in understanding speech, slight muffling of sounds, and difficulty in understanding speech in noisy places or places with poor acoustics.

Severe symptoms of hearing damage can include acute or chronic dizziness, pain, discomfort in the ears. Immediately consult a doctor because medications, when given in time, may minimize hearing loss.

What volume level is safe?

A European Union (EU) scientific body issued an advisory listening from music players using an earphone with unsafe volumes of 89 decibels. How loud is 89 decibels? It is as loud as the noise that you hear from subway trains, motorcycles, workshop tools and lawn mowers. Imagine listening to those directly, all the high and low frequencies directly absorbed by the eardrum. To have an idea of what your ear goes through with everyday sounds, look at this list:

60 db – everyday noise, ringing phone

70 db -at a restaurant

80 db – Heavy city traffic, alarm clock 2 feet away, factory noise, vacuum cleaner, garbage disposal

90 db – Subway trains, motorcycle, workshop tools, lawn mower

100 db – Chain saw, pneumatic drill

110 db – music from a dance club

120 db – sound check from a rock concert speaker sound, sandblasting, thunderclap

130 db – jet take off and gunfire.

Most music players’ decibel output is from 80 – 115 db and using a noise-canceling set of earphones could boost the audio up to 9 db more. That’s about a total 124 db.  So when you listen to your player at its maximum volume, that’s almost exposing your ears  to the sound of a jet taking off or a gunfire.

What should be done to prevent the loss of hearing?

We can’t eliminate the use of earpieces  altogether, but  if you can use headphones instead of earphones. If you must use earphones, do the the 60 percent/60 minute rule which researchers recommend. Listen to your  music players with earphones for just about an hour a day with volume level of just about 60 percent of its maximum volume. Use a noise canceling earphone so you won’t  have to crank up the volume.

When you’re no longer able to hear what the other person next to you is saying while listening to music, then that level is already unsafe. To your hearing and  your overall safety, especially when commuting. Same goes for other sound sources – don’t stand too close to loud speakers and use hearing protection when you’re exposed to loud noises for a long period of time, specially when work-related.

Technology should  work for you, or  in this case, entertain you. Let it stay that way.

Web Reference:

http://www.cdc.gov/niosh/topics/noise/stats.html

http://gilmore2.chem.northwestern.edu/articles/hearing_art.htm

http://www.msnbc.msn.com/id/9314984/ns/health-health_care/t/more-headphone-use-leading-hearing-loss/#.T-j2GXPWyXd

http://www.usatoday.com/tech/products/2009-09-28-eu-volume-mp3_N.htm

 

 

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