Showing posts with label arouse. Show all posts
Showing posts with label arouse. Show all posts

Sunday 25 September 2016

Receptivity, hearing loss and dancing hairs in your ear

Hearing is such a wonderful sense. We forget how unique it is. Until we lose it. I have several family members whose hearing is severely damaged because of exposure to loud noises. In those days farmers didn't use ear muffs so machinery and the firing of shotguns did irreparable damage to their hearing. The effects of this often only show themselves in later years. It is particularly hard to learn these vital lessons when the effects are not immediate. My eldest brother returned from a punk rock concert forty years ago, where he had been standing a little too close to the wall of enormous speakers at the event. For three days he had a ringing sound in both ears and it lasted long enough that he thought permanent damage had been done - it wasn't, he was lucky. Who would've thought years later that the very headphones we use to protect the ears of workers are now damaging the ears of our young who blast themselves incessantly with load music. 

We lose your hearing in many different ways and for many different reasons. Conductive hearing loss is when there is a problem in the transmission of sound to the inner ear. Wax and ear infection or middle ear ossicles (when the tiny bones transmitting the vibrations on the ear drum can no longer do their job) can all contribute to this form of hearing loss.  It is sobering to think that the ear drum which is the fragile link between the outer ear and the middle ear is only 10mm in diameter.  However small that appears, the drum thickness is tinier still at only 0.08 mm.  It can be easily ruptured by excessive noise, pressure or physical trauma.  For those among us who insist on jamming ear buds in their ear to clean them - remember a typical sheet of paper is thicker than your ear drum.  Hearing is a sensitive business from every point of view.

This fragility is matched by the bones, the ossicles, which are on the other side of the ear drum resting against it to pick up the vibrations of the drum. The ossicles are the three tiniest bones in the whole body and form the coupling between the vibration of the eardrum and the forces exerted on the oval window of the inner ear.  This system is connected to the cochlea which looks a bit like a shell.  It has tiny hairs inside that vibrate and transmit the sound to our nerves in the brain.  Usually, age related hearing is when these tiny hairs become damaged and die off.  Our high frequency hair cells die off before low frequency ones and we lose some every year.  If you want to see what these hairs look like, check this out.  You need to press the video button to actual see the hair dance to music.



If you have ever wondered how it sounds to have a cochlea implant you can experience it here (click on link below and listen to both tracks).  I must admit I was disappointed with the results but then my expectations were high.  If you cannot hear at all then this must seem like unbelievable progress.  For Beethoven losing his hearing must have been a torment almost impossible to endure.


To see how wonderful these implants can be for those experiencing deafness this young boy's face says it all.


It is startling to discover that the young generally are more receptive.  They literally hear a much broader frequency range than older people.  Another fascinating feature is that if you lost 166,000 photoreceptors in a retina of your eye you would not be able to see a patch in your vision smaller than the moon’s image.  Everything else would look okay. However, destruction of 166,000 hair cells in your ear would result in disequilibrium and profound deafness.  

We need to respect this sense so much more than we do at present.  Think of an inertial guidance system, an acoustic amplifier and a frequency analyser inside the volume of a marble and be impressed.  Hair cells detect motions of atomic dimensions and respond 100,000 times per second.  

Remember that over time, repeated exposure to loud noise and music can cause hearing loss. To put that in perspective we need to know a few facts.
  1. The decibel (dB) is a unit to measure the level of sound.
  2. The softest sound that some humans can hear is 20 dB or lower.
  3. Normal talking is 40 dB to 60 dB.
  4. A clap of thunder from a nearby storm (120 dB) or a gunshot (140-190 dB, depending on weapon), can both cause immediate damage.
  5. A rock concert is between 110 dB and 120 dB, and can be as high as 140 dB right in front of the speakers.
  6. When listening to a personal music system with stock earphones at a maximum volume, the sound generated can reach a level of over 100 dBA, loud enough to begin causing permanent damage after just 15 minutes per day!
But it is the effect that this sense can have on our spirit that surprises me constantly.  Just as we can damage this amazing organ with abuse, when used appropriately it be transformative.  I love these quotes on what music can bring to all our lives.

“..although sounds are but vibrations in the air which affect the ear's auditory nerve, and these vibrations are but chance phenomena carried along through the air, even so, see how they move the heart. A wondrous melody is wings for the spirit, and maketh the soul to tremble for joy.”

`Abdu’l-Bahá
“Music produces a kind of pleasure which human nature cannot do without.” 

Confucius, The Book of Rites