Hearing Horn

If you have a good hearing, you have something really valuable. Just think! You can listen to the melodious song of a bird, the ripple of a stream, the voice of a loved one. Thanks to your ears, you can receive messages rescue, too, perhaps a car horn, siren or an alarm of fire.

But have you really thought about your amazing sense of hearing? And what of that possessed by other creatures? Even a brief survey can be interesting.

How can you hear?

A glance at the illustration below shows that the ear is much more than this body trumpetlike on the side of your head. This part is just the headset. It captures sound waves and sends them to the interior, along the ear canal. In this document are tiny hairs and wax producing glands. Their goal? To prevent dust, insects, and so on, to go deeper and cause damage.

When sound waves reach the end of the canal, they strike your eardrum, composed of thin fabric taut. The resulting vibration is amplified and transmitted to the middle ear by three bones minute, the bones of the ear. They are commonly called the hammer, anvil and stirrup because of their shapes. The bracket "taps" of the membrane of the window "oval", the transmission of vibrations to your inner ear filled with fluid. The sound waves also enter the inner ear through the round window "," under the window "oval." Some waves, even travel through your skull bones in the inner ear.

Above the central hall of the inner ear are the semicircular canals. The movement of fluid in the help you maintain physical balance. However, the hearing is associated with the cochlea. Sound waves passing through all the moving fluid basilar membrane of the cochlea. In turn, its movement causes the vibration of hair cells that make up the organ of Corti. This movement stimulates the nerves attached to the hair cells. Finally, these nerves, through the auditory nerve, sending messages via electrical impulses to the heart of the audience of your brain. All this is well known, but how a person can understand such signals continues to frustrate scientists.

A word on what you hear

You may not hear all the sounds around you, and it is a good thing. Like a babe in arms, your range of hearing can take place 15 to 30 000 cycles or vibrations a second. But that was far below 15 cycles. Why, when you hear your own heartbeat, even your bones and muscle movements!

Although it has certain limitations, your voice is amazing scope. As individuals differ, in general, the loudest sound that can tolerate is 2,000,000,000,000 times greater than the least perceptible sound! Indeed, the human ear has the maximum sensitivity of practical needs.

As the years pass, of course, imperfect humans experience progressive loss of hearing ability. Among other things, it is because the inner ear tissues lose their elasticity. The upper range hearing loss would be in 30,000 cycles when a baby is at 4,000 cycles when you're eighty. However, even this is enough for normal conversation.

Truly a masterpiece!

Your ears have integrated protection against the extremely loud noise. Of course, a sudden explosion nearby may cause excessive vibration which could cause irreparable damage to your hearing aid complex. But if a loud noise is gradually developing, fast-acting muscle can "lower the volume. The tympanic membrane is tightened to reduce vibration, and the muscles of the middle ear twist the ear bones. Thus , the bracket does not transmit the vibrations through the window wide "oval" in the inner ear.

Protection is also provided by the Eustachian tube, from the nasal cavity to the middle ear. This passage leads and equalizes the air pressure inside your eardru.