Special Feature - Hear Music w/o Ears (sort of...)
September 2008 --
If you have ever used earbuds, those small headphone-like things most people have surgically attached to their ears these days, then you may know that you are at risk of hearing loss later in life. A recent study published in the Italian journal, "Medicina del Lavoro" concluded that people who listen to music using earbuds, and have the volume at or close to the maximum allowable, exceed the limit for daily occupational noise standards.
This means that earbuds are dangerous to our ears, because they can exceed 100 dBA (A-weighted decibels, a specific curve used to measure the real sound pressure level for environmental noise) a level which according to the US Occupation Safety and Health Administration is safely mandated for only 1-2 hours of exposure. Basically, earbuds dramatically increase the pressure on our eardrums to levels that are dangerous for long periods of time. The average iPod user has earbuds in their ears around one to two hours a day. Therefore, earbuds can potentially cause hearing loss.
With a large number of "youths" (which could mean 12-40 yrs.) using these types of listening device, we could see a new generation of hearing loss far greater than the number we are experiencing today. Just to give you some perspective, 100 dBA is about the same as a loud orchestra, or a moderately loud rock band. It is tolerable but would be considered "loud" by the average person. Keep in mind decibels use logarithmic scales (non-linear) so 110 decibels is 10 times more energy, and 120 decibels is 100 times the energy of 100 dBA. If we look at 110 dBA, we are getting into the loud rock band type of loudness. For some this could be uncomfortable past a minute or two of exposure. At the peak, we have 115 dBA which is the loudest point of an average sized rock concert. This is loud, and many people would consider plugging their ears at that point. 120 dBA is the threshold of physical pain.
Earbuds have the potential of producing this level of audio given the fact that they are so close to the eardrum. However, there is a potential solution/alternative. Audio Bones are the world's first high-fidelity bone conduction headphones (http://www.audioboneheadphones.com). They fit right next to the bone in front of your ear, sending the sound straight to the inner ear, bypassing the eardrum. The best feature is that this design leaves your outer ear completely open and free to hear the world around you.
This technology dramatically reduces the risk of high dBA exposure for portable music listening devices. As well, many people do not have the cartilage necessary to hold earbuds in place, which is technically a disability in this circumstance. The Audio Bones do not require this special cartilage, and instead attach directly to your head. Moreover, it allows people who normally cannot hear music through their eardrums the ability to listen to music! In fact, the Audio Bones' website remarks about how Ludwig van Beethoven discovered this facility by attaching a rod to his piano and clenching it with his teeth to hear the music through his jawbone. Very sci-fi at the least.
However, there is a catch. The audio quality, compared to speakers or earbuds/headphones, is not nearly as crisp. BUT it seems to work just fine for casual, passive listening, which if you read the Dr. Rhythm feature article two weeks ago, you would know this is the growing trend amongst the current music listening culture. If nothing else the technology is worth looking into, especially if you are a parent concerned about the unhealthy effects of your child's iPod/Zune habits.
There is also an alternative to bone conduction, which is called cartilage conduction. The company Zelco sells their own version of conductive sound technology called the Outi which literally clips onto the outside of your ear. Get it? -- an Outi, not an Inni? One side effect is a noticeable vibration that one can feel on their ear when using this technology due to how the device is producing the "sound." People have claimed that the audio quality is much better than bone conduction, with the only drawback being how loud the sound is to a nearby listener. Though it will be worth it when you cannot hear your cubicle-mate talk about Spencer and Heidi on MTV's the Hills. And most importantly your eardrums are perfectly safe!
The most compelling aspect of these technologies is the ability to provide a listening device for people with damaged eardrums. Hearing-aids have been using these phenomena for quite a while, but never has the general market created a new demand for such a product. This is yet another example of how assistive technologies can benefit more than just their target demographic. Any one of us could suffer from hearing loss later in life, especially as a result from noise exposure. The Audio Bone and Outi are great examples of how we can avoid this potential hearing loss, as well as benefit those who already have lost their hearing. What a perfect concept.
In good musical health,
Dr. Rhythm
