Fear the Ear (Buds)

Hear Today, Gone Tomorrow.” “Listen to Your Buds.” “Make Listening Safe.” These are just a few of many campaigns to discourage individuals, especially young teenagers, from improper use of ear buds and headphones.

 

Why is this message so prevalent in media today?

Since their creation in 1910 by Nathaniel Baldwin, headphones have always been a danger to our hearing. The advent of the ear buds style headphones has brought the risk of hearing loss to more probable level. Ear buds, which sit further in the ear canal, are more powerful and dangerous than in the past. Ear buds do a poorer job at cancelling background noise in comparison to the old-style supra-aural (over the ear) headphones. “Hearing loss among today’s teens is about 30 percent higher than in the 1980s and 1990s,” says Dr. Sreekant Cherukuri, an ear, nose and throat specialist from Munster, Indiana. This higher prevalence of hearing loss is directly related to the increase of the availability of technology causing an increase of use of personal music players. “Probably the largest cause [of hearing damage] is millennials using iPods and [smartphones],” says Dr. Cherukuri. Listening to your iPod at more than 50% (which is over 80 dB) for 15 minutes can have a devastating and permanent effect on your hearing abilities, according to the National Institute of Health.

Is the message actually prevalent in the media?

If you Google “noise-induced hearing loss”, “safe listening iPod” or “ear buds bad”, the number of educational campaigns and websites dedicated to the dangers of loud noises will make you think you’ve been missing the daily commercials or public health announcements in the media. Although different groups have attempted different campaigns to reduce the number of individuals at risk for noise-induced loss, the prevalence is simply increasing. The World Health Organization estimates that over 1.1 billion people worldwide are at risk for hearing loss due to unsafe listening practices.

Despite the attempts at reducing this dangerous health behavior, teenagers and young adults are listening to their iPods TOO loud. A study in 2010 in the American Journal of Audiology estimated around one-third of college students were occasionally using their MP3 players at maximum volume levels. Another study in 2011 appearing in the Journal of Speech, Language and Hearing Research suggests that nearly 60% of students at a major New York City college were found listening to their personal devices with headphones at volumes greater than 85 dB.

These statistics indicate that knowledge and awareness about noise-induced hearing loss are low amongst teens. The lack of knowledge catalyzes a lack of concern for noise-induced loss. A survey of Teens and Adults about the Use of Personal Electronic Devices and Headphones in 2006 identified that 47% of teens say they are not concerned about hearing loss from the use of personal audio technology. This attitude is common amongst young adults, as it is hard to foresee long-term consequences of present decisions. The Today Show interviewed a 22 year old with noise-induced hearing loss who summed up the perspective of teens worldwide, “You don’t think anything is going to happen.”

What happens to the ears?

Ears are extremely complex and delicate structures. When sound is introduced into the ear, there are many structures of our inner ear that can be affected or damaged. The inner ear houses the hearing organ, called the cochlea, which transforms sound (traveling acoustically through the movement of air molecules) into electrical nerve impulses so information can reach the brain. The cochlea is similar to a piano or keyboard, organized tonotopically, or from low pitches to high pitches. The high pitches are closest to the entrance/base of the cochlea and the low pitches are at the top of the cochlea. Each key on the cochlea keyboard has hair cells that act as sensory receptors, moving and transforming the sound to nerve impulses. When loud sound enters the ear, there are two potential structural effects:

  1. Stereocilia, the hair-like projections that sit on top of the hair cells, can be bent or torn off with high levels of sound. Unlike in birds, once these stereocilia are torn off, damaged or die, they are unable to grow back.
  2. The connection point between the hair cell and the auditory nerve, call the synapse, is especially vulnerable to noise. “You can lose up to 90 percent of your cochlear nerve fibers without a change in the ability to detect a tone in quiet,” Dr. Charles Liberman, director of Massachusetts Eye and Ear Infirmary’s Eaton Peabody Laboratory said. “Tone detection in quiet is the basis of the threshold audiogram — the gold standard test of hearing function. The fact that thresholds may transiently elevate and then recover within hours or days after an acoustic overexposure doesn’t mean that the inner ear has recovered.” This phenomen has been recently coined as hidden hearing loss. If a hair cell has lost its synapse, it no longer responds to sound and within a few months or years, the neuron will simply disappear. This reduces the amount of the information channels for auditory information to get to the brain. Once it disconnects, there is no possibility for reconnection.

The higher pitches, near the entrance of the cochlea, are generally affected first. Higher pitches do not just refer to the impossibly high dog whistles. There are many consonants (k, t, th, s, sh) that exist in the high pitches. A reduction in hearing abilities can cause speech to sound mumbled.
Another common symptom of noise-induced loss is tinnitus. Tinnitus is ringing or buzzing in the ears when there is no external stimulus or sound. Tinnitus can be occasional or constant, in one ear or both. Tinnitus is a debilitating symptom that can impact an individual’s life, from hearing soft speech to sleeping.

How can we fix this?

As of now, there is no solution for noise-induced damage to the inner ear structures.

There is talk of trying to regrow hair cells that have died off due to noise damage. The University of Kansas is currently conducting a clinical trial but has not had conclusive conclusion yet.

Prevention is the best defense our ears have against noise-induced hearing loss.

Here are some tips for reducing your risk for attaining noise-induced loss:

  1. Use the 60-60 rule: keep volume below 60% and listen for less than 60 minutes a day. There is a feature to limit the volume on your iPod/iPhone so you don’t accidentally turn it up too loud.
  2. Buy background-cancelling headphones so you don’t have to compensate for loud noises around you.
  3. Carry hearing protective devices with you when you attend bars, concerts, sporting events, workout classes and other dangerous listening environments. Advocate for your hearing at these places! Is the music TOO loud at your Jazzercise class? Ask your teacher to turn it down and/or do not be close to the speaker.
  4. Turn down your car radio! Make sure you would be able to hear someone talking to you from the backseat. If you can’t pass that test, your music is too loud.

 

 

References:

Acoustical Society of America (ASA). “Noise-induced ‘hidden hearing loss’ mechanism discovered.” ScienceDaily. ScienceDaily, 7 May 2014.

The Today Show

Huffington Post

 

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