Bookmark us!

Global Bioweather

“we forecast your wellbeing”

The inner ear

The oval window of the middle ear is the entry to the vestibular canal within the fluid-filled and snail-shaped cavity, the cochlea of the inner ear. During sound activity, the stirrup strikes the membrane of the oval window, creating a travelling wave within the fluid of the canal. The wave wanders along the full length of the cochlea and returns via the tympanic canal to a second window, the round window (fenestra cochlea), where the pressure of the wave equalizes.

Along the way, the wave passes over thousands of hair-like sensors. Like an ocean wave moves the kelp at the bottom of the sea, the sensors also bend with the motion and trigger nerve impulses. The auditory nerve transmits the coded impulses to the brain, where the message is interpreted as a specific sound or noise. Loud noise can damage the sensors. They may become sluggish, may stick together or may even break off. Once destroyed, they don’t regenerate and the more sensors become damaged the worse your hearing loss will be.

Sound doesn’t exclusively travel through air. Sound pressure waves may also reach the inner ear through vibrations of the bones of your skull. The vibrations are able to stimulate the sensitive receptors in the cochlea and you may hear some of your voice, even if both auditory canals are blocked.

Index

and Health

Noise

I have to mention the three semicircular canals on top of the cochlea. They have nothing to do with hearing, but help you maintain your balance. Without them you wouldn’t be able to walk. They function similar to the cochlea whereby a fluid moves within the canals and bends hair-like receptors. The brain interprets the resultant impulses and instructs certain muscles to keep you upright, for example.

Picture source: National Institute of Health