By Christopher Byrne
“If the music is too loud, you’re too old.” Have you heard that? It’s a supposedly humorous comment reflecting the thoughts of young people regarding the, ahem, “elderly” (30-something and above). But it’s not funny: noise-induced hearing loss in children and youth is a serious problem—and getting worse.
iPods (and similar MP3 players) are everywhere today, and when not used safely, they contribute to noise induced hearing loss, the second most common form of hearing loss today. That’s very bad news. But there’s also good news: Noise-induced hearing loss (NIHL) is 100 percent preventable.
Let’s look at some present facts in the United States. The National Centre for Environmental Health has recently revealed that 12.5 percent of children between the ages of six- and nine-years-old have a noise-induced hearing loss. That’s 5.2 million children, which is an astounding number of children, according to Ellen Rhoades, (Ed. S. and Cert. AVT), to have a problem previously thought to occur mostly in adults. Further, Ellen reports a University of Oregon study showing that 16 percent of 6- to 19-year olds have early signs of hearing loss at the range most readily damaged by loud sounds. When we add the fact that 2.4 million people between the ages of eighteen and thirty-four have hearing loss, you can see the trend—the problem is growing and at a very rapid rate.
What has caused the increase of NIHL in such a short time, you may wonder?
A leading factor appears to be exposure to damagingly loud sound over time as delivered through personal music devices set at “high” volume.
The toy industry and related agencies have monitored sound producing toys for a number of years now in an effort to reduce any potential harm to hearing that could be caused while using these toys inappropriately. For example, the European Standard on toy safety (BS EN 71-1) was adopted in the UK in 1998 and specifies noise limits for different types of toys. Likewise, in Europe, iPods are legally capped for volume at 100 decibels.
Currently, there is no U.S. limit on the volume level of personal music devices. Children, particularly, and youngsters in general, may not be aware of hearing damage occurring while using personal music devices because the loss of hearing is gradual and there are few pronounced early symptoms. With prolonged exposure, the hearing loss is also permanent.
Here’s what happens. The human ear is divided into three parts from the external ear to the middle and then inner ear. Sound is collected in the external ear, converted to mechanical energy by the eardrum and small bones of the middle ear, then delivered to the inner ear where it is translated into electrical energy to be transported to the brain in the form of nerve impulses. The hearing loss we are concerned with occurs in the inner ear. Prolonged exposure to loud sound (or an intense burst of loud sound such as that of a firecracker) can permanently damage the hair cells located in the inner ear that respond to sound frequencies (pitch) and translate them into the electrical impulses then sent to the brain. This damage usually occurs in what is perceived as the higher pitch sounds within speech. The result is hearing loss that makes it difficult to understand speech or to hear the sibilant sounds such as s-, sh-, th-, ch-, etc., as example. Once the cells are damaged or destroyed, this ability to perceive/understand conversational level speech cannot be restored because the damage is permanent.
Think of this. We detect normal, conversational speech at a level of 60 decibels (perceived as loudness); a whisper in quiet conditions at 30 to 40 decibels (dB). O dB is considered the lowest level at which sound is detectable and 140 dB is equivalent to standing on an airport runway next to a jet taking off. It’s only at the more intense levels, such as the jet takeoff, that loud sound might be perceived as painful. Hearing damage can occur beginning at about 80 dB with sustained exposure over a period of hours, and possibly at a lower level in infants. Stereo headphones set at 100 dB (the cap in Europe) can harm ears (hearing) in two hours. One study of portable compact players found that a high volume setting ranged upward from 91 to 121 dB. That’s louder than a rock concert, a sandblaster or a car horn delivered directly into the ear.
In a nutshell, any noise level that is “loud” enough to interfere with speech causing people to need to raise their voices to be heard is a level loud enough to cause hearing damage over time.
So, back to personal music players and similar listening devices. What should we do?
With children, it is important to limit the amount of time set aside for listening to short periods and with adult monitoring of loudness level. (The ears, after all, need time to rest and recover from stimulation just as we do from other forms of exercise.) It is also important, we feel, not to use earphones that fit inside the ear canal with younger children. (Earphones inside the ear actually increase the volume by up to almost 10 decibels above the same sound signal delivered through external speakers or even headphones.) Also, because very young children are more prone to middle ear infections than older children and adults, it’s best to avoid inserting earphones into the external canal and risk sound intensity damage to hearing due to an existing temporary middle ear hearing loss. Besides that, it’s much more difficult for the adult to monitor if the child chooses to increase the volume of the device when using earphones.
For young children, we strongly advocate adult-monitored listening through a standard external speaker system, or over-the-ear headphones if necessary. With older children, we recommend education regarding hearing damage and adult guidance as to what is likely “too loud.”
Don’t get us wrong. iPods and MP3 players, just as gaming devices, are fun! And what increasingly style- or trend-conscious child all the way down to preschool isn’t clamoring to have one? We certainly love ours.
We’re simply saying that noise-induced hearing loss is a very real and increasing problem. Once the damage is done it can’t be undone. So we “too old” adults need to say, “If the music’s too loud… it’s too loud! It’s up to us to help children of all ages avoid damaging something so precious as the ability to hear.