MIT researchers discover a new hearing mechanism

An article on the Massachusetts Institute of Technology's (MIT) news website published on October 10, 2007 reported that MIT researchers have discovered a mechanism inside the inner ear that functions in a different way. For over 50 years, it has been known that sound waves inside the cochlea travel in an up-and-down manner. But the research team noted in the article has found that sound energy can also be carried by a traveling wave that moves from side-to-side. Read the article to learn more about the potential impacts of this discovery.

Click here to read the article: MIT finds new hearing mechanism

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Credit: Ghaffari, Aranyosi, and Freeman, MIT

Dancing outer hair cell

This post is just another reason why our auditory system is so fascinating. To appreciate this movie, I need to give a short explanation of some auditory structures and their role in hearing.

The cochlea is a snail-shaped structure in the inner ear (beyond your eardrum) that is the sensory organ of hearing. There are microscopic hair cells with stereocilia at the tips within the cochlea that are responsible for moving in response to vibrations. Basically, it is the motion of the sensory hair cells that allows signals to be sent to the brain via the auditory nerve and process sounds we hear.

The image on the right shows a top view of the stereocilia of an outer hair cell in the cochlea. Credit: www.neuroscience.cam.ac.uk

Hair cells are most sensitive and contract at specific frequencies. They can degenerate over our lifetime with age and can also be damaged when we are exposed to very loud sounds, which is why it is important to always protect your ears. UK Scientist, Jonathon Ashmore was able to isolate a single outer hair cell and make it dance! That's right, dance...presenting you with the DANCING OUTER HAIR CELL!
Read an explanation of movie from Ashmore's website here: http://www.physiol.ucl.ac.uk/ashmore/hairexpl.htm

Boys and Girls Club of Burbank presentations

The hearing awareness conservation presentations at the Boys and Girls Club of Burbank were a hit with the summer day camp students!

The topics presented to the first-third graders included importance of hearing, how we hear, identifying very loud sounds and the danger, and how to protect your hearing.

The fourth- eighth graders received a similar but more in-depth presentation that also encompassed measuring sound levels using a sound level meter, noise-induced hearing loss and why not to use cotton swabs in the ear. After receiving a warm welcome, both groups were respectful, attentive and seemed eager to learn about hearing. I was thrilled to have had an opportunity to share my knowledge with them. It wonderful to meet students and answer their hearing-related questions. I hope to visit them again soon.



















Picture of me with the winners of the quiz session. The Earbud t-shirt prizes and Earbud brochures were courtesy of House Ear Institute. Many thanks to House Ear Institute for their continued support of my efforts!

Money magazine reviews “Noise-Isolating” earbuds

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The current issue of Money magazine features connecting a review of noise-isolating earbuds to a topic that appears to be receiving more attention in recent months than it has in the past: noise-induced hearing loss. With the popularity of mp3 players, as well as the risk they present with improper use, some magazines are finding good reason to discuss the hearing factors involved in consumer-product reviews. “Easy Listening: Noise-isolating earbuds deliver music in peace, no matter what’s going on around you” by Wilson Rothman channels the main healthy hearing message using a consumer-friendly approach.

Rothman reviews six low-priced model earbuds and declares Creative’s Zen Aurvana, priced at $100, as the Field Test Winner. But before he names the winner, he notes the National Institute on Deafness and Other Communication Disorders ( www.nidcd.com), which states that exposure to sounds louder than 85 decibels for an extended period of time can cause hearing loss. He further mentions a significant detail that most consumers are unaware of: the maximum volume level on the iPod is 115 decibels. Rothman compares this sound level to a chain saw and grounded jet and provides an alternative to turning up your music to block background noise – buy a pair of decent noise-isolating earbuds to use with your mp3 player.

Although these are not “noise-canceling” headphones as Rothman points out, he covers all the essentials in his review of some brand-name noise-isolating earbuds and gives consumers a range to choose from. I use the Apple In-Ear earbuds and agree with Rothman that the price and sound quality are good but I think it has a couple drawbacks. My ear canals are fairly narrow and they fall out of my ear canal too often while exercising even though I use the appropriate size inserts. Without a nice tight fit, it is difficult to achieve its noise-isolating capacity.

Hearing in the news - L.A. Times

It's always nice to find an audiology article in the newspaper since it doesn't happen quite often enough, at least in my opinion. However, in the past year I have noticed a slight increase in news about noise-induced hearing loss.

"Like an earplug in a pill," published in the Los Angeles Times on July 2, 2007, discusses noise-induced hearing loss and otoprotectants.

Here is a snippet of the article. You can read the full article at: http://www.latimes.com/features/health/la-he-lab2jul02,1,4407246,full.story

"TED AX knows he should wear earplugs when he leans into the noisy engine compartment of an MG sports car. He's been working among clanging metal and whirring power tools in garages for the last 15 years and has already developed tinnitus, a ringing in the ears that is one of the most common symptoms of hearing loss caused by excessive noise."

Upcoming Presentation

On Thursday, August 2, I will be conducting hearing conservation awareness information to the members of the Boys and Girls Club of Burbank, CA. I'm thrilled to have this opportunity to speak to 1st-8th graders about dangerous sound levels and method of protecting their hearing.

Free ear plugs and hearing health materials will be provided courtesy of the Hour Ear Institute's "It's How You Listen That Counts," an awareness campaign for teens. Also, Ear Bud t-shirts will be rewarded as a prize during a short quiz session.

For more information about the event, visit their website: Boys and Girls Club of Burbank - News & Events