PVCC Puma Press: March 2006

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	Photo by Chelly Brown
	Kaci Padgett, Megan Kirkes, and Sarah Gray listen to music while relaxing in the student lounge at PVCC. The small size of MP3 players make them popular and convenient for many young people.
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Laughter rings out in the student union. PVCC students, Sarah Gray, Megan Kirkes, and Kaci Padgett are sitting together chatting. Some students turned in the direction of the laughter; others didn’t seem to hear it. The latter may have been listening to an iPod or maybe they have hearing loss from one.

Millions of young people listen to music on portable audio devices. This growing trend has become the subject of research. According to a poll released March 14, 2006, the American Speech-Language-Hearing Association found that more than half of high school students have at least one symptom of hearing loss associated with the use of popular music devices, such as iPods and MP3 players.

• 28 percent of high school students say they have to turn up the volume on their television or radio;

• 29 percent of high school students often say “What?” or “Huh?” during normal conversations;

• 17 percent of high school students experience tinnitus, a ringing in the ears.

On the other hand, 49 percent of high school students say they have not experienced any symptoms of hearing loss.

“I probably have hearing loss, but just don’t know about it,” says Tim Garrison, a music student at PVCC. “There’s no ringing, maybe just pressure sometimes, like when you go to a high altitude and your ears pop.”

The type of hearing loss that can occur from portable audio devices is called noise-induced hearing loss. When an individual is exposed to harmful sounds, such as sounds that are too loud or loud over a long period of time, the sensitive structures of the inner ear can be damaged.

“I honestly think a lot of people play their iPod too loudly, because you can hear it when you walk by,” says Ryan Johnson, a music student at PVCC. “I try to protect my ears because I do a lot of sound mixing, so I need to be able to hear. But also there are times when you really want to crank it,” says Johnson. He plays in a band and the sound can get really loud. “Afterwards, my ears may ring…but it was fun!”

The ear has three main parts: the outer, middle and inner ear. Sound waves enter through the outer ear and reach the middle ear where they cause the eardrum to vibrate. The vibrations move deeper to the inner ear where the hair cells (the nerve receptors for hearing) initiate the production of the nerve impulses. These nerve impulses travel to the brain, which interprets them as sound. It is within the inner ear that the damaged occurs.

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	'Half of all high school students have at least one symptom of hearing loss'
	—American Speech-Language-Hearing Association
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Ear-bud headphones, the small earplugs that fit into the ear canal, have raised concern because the sound they generate projects directly into the ear canal. Traditional earmuff-style headphones offer some diffusion of the sound because they fit around the outside of the ear.

Christopher Castro, a PVCC student, likes to play a turntable loud. “Playing it loud, the bass is always good, too,” says Castro. “Sometimes when the bass is too loud, it massages your ear drum.”

He feels that the loud music may damage his ears, but it seems to recede after a day or two. “The worst time, I had a ringing or buzzing sound in my ears for three days,” says Castro. “It bothers me when I try to hear other things, but it’s worth it; I try to rest between really loud play sessions.”

Ingrid McBride, Au.D, CCC-A, clinical associate professor and director of clinical services at ASU Speech & Hearing Clinic, has another take on the subject.

“There are two things that must be considered in regard to the potential of MP3 players to cause hearing damage: the first is the decibel level, and the second is the duration of exposure. You have to look at both of those things.”

The loudness of sound is measured in units called decibels. The National Institutes of Health and the World Health Organization give examples of decibel measurements for common everyday noises:

• 40 decibels—refrigerator

• 60 decibels—conversation

• 80 decibels—city traffic

• 100 decibels—motorcycles

• 120 decibels—car stereo

• 130 decibels—rock concert

• 140 decibels—gunshot

“Portable audio devices can peak at 120 decibels,” says McBride. “Eighty-five decibels is a safe level if you are listening continuously for eight hours.” Turning the volume one-quarter of the way up is approximately 85 decibels; turning the volume all the way up is about 120 decibels.

Hearing health is the responsibility of every individual, but there is a general lack of public awareness that has triggered law suits. One case involves a Louisiana man, John Kiel Patterson, who filed a class action lawsuit on Jan. 31, 2006, at the U.S. District Court in San Jose, California. He claims that the iPod has potential to cause irreparable hearing loss. Patterson also claims that there are not enough warning labels on the device that state the potential for hearing loss. Most manufacturing companies of these audio devices, including Apple, ship a warning with their products stating that hearing loss may occur if used at high volumes.

“Any audio device has the potential to cause damage to hearing. Just because iPods are more popular doesn’t make them more dangerous than any other device,” says McBride.

The Occupational Safety and Health Administration permits a maximum exposure of eight hours per day at 90 decibels. For every increase of five decibels, exposure time is cut in half. Therefore, the maximum exposure permitted for 95 decibels is four hours; 100 decibels is two hours.

“A good rule of thumb is, if you have to shout, it’s too loud,” says McBride. “For example, if you are at a night club and the noise is over 85 decibels, stay away from speakers, take breaks, rest outside or away from the noise for 15-20 minutes so that the exposure is decreased,” says McBride. “Alcohol and smoking also increase the risk.” According to the American Speech-Language-Hearing Association, alcohol and nicotine, as well as certain medications, can cause toxic reactions to the structures of the inner ear and are considered ototoxic, or toxic for hearing.

After exposure to a loud noise, such as a rock concert, the ear’s sensitivity level will decrease as a measure of protection. There is a shift in the threshold of hearing where only sounds louder than a certain level can be heard. “Warning signs of a temporary threshold shift are if the ears seem stuffy or muffled or there is a ringing in the ears,” says McBride. “Chances are the ears will recover.” These symptoms may last 24 hours or as long as a week, but if they last longer or worsen, then a hearing test by an audiologist is a good idea.

“A gunshot, an impact sound over 140 decibels, does not require continuous exposure and can immediately cause permanent damage,” says McBride. The structures of the inner ear may be severely damaged. This type of hearing loss may be experienced in either one or both ears and may be accompanied by tinnitus that could continue intermittently throughout a lifetime. The damage that occurs gradually over years of continuous exposure to loud noises causes various changes in the structure of the hair cells within the inner ear. It also results in hearing loss and tinnitus.

Noise-induced hearing loss is not reversible, but it is preventable. Knowledge is the key to making good choices in everyday life. People should be aware of the noises that cause hearing damage. When participating in loud activities, wear earplugs or other protective hearing devices that can be found at hardware stores and sporting good stores. It’s also important to protect children who are too young to protect themselves. Finally, when listening to iPods or any other device, follow McBride’s advice: “Limit volume, limit duration and take breaks."