Cicadas Can Cause Permanent Hearing Loss!

Cicadas are pretty darn ugly... But beyond their ugliness and making cars look pretty messed up... the sound they make is not only irritating, but potentially harmful.

Sometime the end of this April 2013, billions of large flying insects called cicadas will make their appearance along with their characteristic stridorous noise. The male cicadas are the ones making this mating noise with "tymbal" soundmakers amplified by large resonance chambers found on body.

Occurring every 17 years, this year's swarm is known as Brood II and has not been seen since 1996. Expected to cover much of the East Coast, the buzz created by these insects can reach 90 decibels... about as loud as a jackhammer. If one is right next to your ear, the sound can reach 120 decibels are equivalent to sandblasting or a loud rock concert. [see noise chart]

At 90 decibels, possible hearing damage may occur if a human ear is exposed to this level noise for more than 8 hours a day. At 120 decibels, less than 15 minutes of exposure can induce possible permanent hearing loss.

So... keep a pair of ear plugs in your purse or pants pocket and use them if the sound starts to get too loud.... or too irritating.

Sources:
17 years in the making, this spring's cicada invasion generates early buzz. NBC News 4/10/13.

Cicada. Wikipedia

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Noise Charts as It Relates to Hearing Damage

Fun hearing facts collected from a variety of sources...

Environmental Noise
Weakest sound heard	0dB
Whisper Quiet Library at 6'	30dB
Normal conversation at 3'	60-65dB
Telephone dial tone	80dB
City Traffic (inside car)	85dB
Train whistle at 500', Truck Traffic	90dB
Jackhammer at 50'	95dB
Subway train at 200'	95dB
Level at which sustained exposure may result in hearing loss	90 - 95dB
Hand Drill	98dB
Power mower at 3'	107dB
Snowmobile, Motorcycle	100dB
Power saw at 3'	110dB
Sandblasting, Loud Rock Concert	115dB
Pain begins	125dB
Pneumatic riveter at 4'	125dB
Even short term exposure can cause permanent damage - Loudest recommended exposure WITH hearing protection	140dB
Jet engine at 100'	140dB
12 Gauge Shotgun Blast	165dB
Death of hearing tissue	180dB
Loudest sound possible	194dB

OSHA Daily Permissible Noise Level Exposure
Hours per day	Sound level
8	90dB
6	92dB
4	95dB
3	97dB
2	100dB
1.5	102dB
1	105dB
.5	110dB
.25 or less	115dB

Perceptions of Increases in Decibel Level
Imperceptible Change	1dB
Barely Perceptible Change	3dB
Clearly Noticeable Change	5dB
About Twice as Loud	10dB
About Four Times as Loud	20dB

Sound Levels Found in Music
Normal piano practice	60 -70dB
Fortissimo Singer, 3'	70dB
Chamber music, small auditorium	75 - 85dB
Piano Fortissimo	84 - 103dB
Violin	82 - 92dB
Cello	85 -111dB
Oboe	95-112dB
Flute	92 -103dB
Piccolo	90 -106dB
Clarinet	85 - 114dB
French horn	90 - 106dB
Trombone	85 - 114dB
Tympani and bass drum	106dB
Walkman on 5/10	94dB
Symphonic music peak	120 - 137dB
Amplifier, rock, 4-6'	120dB
Rock music peak	150dB

Sources:
The National Institute for Occupational Safety and Health (NIOSH)

Binge Listening: Is exposure to leisure noise causing hearing loss in young Australians? [pdf] – Australian Hearing, National Acoustic Laboratories

Occupational Noise Exposure. OSHA




   

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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

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