Human Ear Contains a Built-In "Ear Plug"

According to one Australian researcher, by just chewing a gum or singing/talking loudly, one could be protecting your ears from noise-induced hearing damage. How???

It is not common knowledge that the human ear contains two muscles that attach to the middle ear bones called the stapedius and tensor tympani muscles.

The middle ear bones, composed of the malleus, incus, and stapes, are what transmits sounds from the eardrum to the cochlea which allows a person to hear. The stapedius muscle attaches to the stapes and the tensor tympani to the malleus.

If something prevents the middle ear bones from vibrating, that effectively dampens the sound transmission from the eardrum to the cochlea... just like an ear plug or a bad case or earwax dampens sound transmitted through the ear canal to the eardrum.

SO... if the middle ear muscles tighten which are attached to the middle ear bones preventing them from vibrating, less sound is transmitted to the cochlea... just like an ear plug, except it is built-in.

Just how effectively does this reduce sound?

According to the researcher who has been studying this phenomenon, by about 30 decibels (or 1000x fainter).

That's about the same as foam earplugs!

How does one "activate" the middle ear muscle contraction?

By chewing a gum or singing/talking loudly!

Some individuals can sense this contraction if they close their eyes and try to "pull the muscles around the ears together"... a fluttering sensation inside the ear may be heard/felt which is the contraction of the middle ear muscles. In rare patients, this contraction may occur involuntarily and continuously.

SO... if you happen to have forgotten your ear plugs and are attending a very loud rock concert, chew gum and/or sing along with the band loudly! This may actually protect your hearing!

Of course, it's better to wear hearing protection, or better yet, avoid such circumstances altogether.

Read more about this here.

Reference:
How do middle ear muscles protect the cochlea? Reconsideration of the intralabyrinthine pressure theory. Journal of Hearing Science 2011; 1(2): RA 9 - 23

Xylitol (Natural Compound) to Prevent Recurrent Sinus and Ear Infections?

I only recently became aware of a natural sugar compound called "Xylitol" from a colleague's blog, BoogorDoctor, managed by Dr. Russell Faust. I certainly have never heard of it during medical school or surgical training.

This naturally-occurring sugar substitute apparently has all sorts of anti-bacterial as well as anti-fungal properties and has been known to doctors and scientists but hardly marketed or promoted in any fashion.

However, the importance of this compound is that it DOES appear to significantly decrease the incidence of ear infections and sinus infections when used regularly (in essence, xylitol mixed in with salt-water sprayed into the nose several times a day).

It's cheap (around $10) and at least from the studies I've reviewed, does seem to work. However, to be fair, it only works when given regularly even if healthy. If given when sick, it does not work (see this study). Also to be fair, there are some studies that suggest that xylitol does NOT work at all.

However, given there are minimal (if any) side effects, it is certainly something worth trying before surgical consideration, especially in children.

Why is this compound not more well-known?

Probably because it's cheap and therefore not a money-maker... which means not a lot of dollars goes into marketing the product whether directly to patients or doctors.

In any case, you can get it on Amazon.com here (or possibly at a local pharmacy).

I should also mention that Xlear is the only product series that uses the optimal concentration xylitol (others use only the bare minimum concentration to meet ingredient inclusion).




References:
A Story About a Sugar: The X-Factor. Blog by Dr. Faust

Xylitol as a prophylaxis for acute otitis media: systematic review. Int J Audiol. 2010 Oct;49(10):754-61.

A novel use of xylitol sugar in preventing acute otitis media. Pediatrics. 1998 Oct;102(4 Pt 1):879-84.

Xylitol chewing gum in prevention of acute otitis media: double blind randomised trial. BMJ. 1996 Nov 9;313(7066):1180-4.

Failure of xylitol given three times a day for preventing acute otitis media. Pediatr Infect Dis J. 2007 May;26(5):423-7.

Xylitol administered only during respiratory infections failed to prevent acute otitis media. Pediatrics. 2002 Feb;109(2):E19.

Chewing Gum Improves Memory?!!

I came across interesting research that hinted at the possibility that chewing gum improves tasks that require memory recall. This was first suggested in a study published in 2002 in the journal Appetite where chewing gum was found to selectively improve aspects of memory in healthy volunteers. The researchers took seventy-five adults and separated them into three groups: those that chewed gum during a twenty-minute test of memory and attention, those that mimicked the chewing movement, and those that did not chew at all.

They found that people who chewed scored better on long- and short-term memory tests (measured by word recall).

The authors speculated on three possible explanations: brain activity in the hippocampus increases while people chew, so this might help with memory; gum chewing promotes the release of insulin, which might indirectly affect memory; and the most straightforward—chewing can increase heart rate slightly, and this increased blood flow could deliver more oxygen to the brain.

Follow-up studies in 2004 supported these initial findings.

A more recent study in 2009 using 101 student volunteers found that it wasn’t the gum per se but any candy (cinnamon candy in the study) or oral stimulus can help a person remember information. Based on this study, it was felt that the oral action as well as the scent of the candy/gum served as a memory cue for information.

Maybe those gum-smacking kids in class did know something the rest of us did not.

Fortunately, fear not teachers... There are other studies that have been done that have not replicated these results at all and even contradicts them.

Chewing gum can also exacerbate/cause TMJ problems.

Image taken from Wikipedia.