Your Hearing

How We Hear

The ear is an amazing and complex organ comprising three parts: the outer ear, the middle ear and the inner ear. From the inner ear the auditory nerve transmits information to the brain for processing. Below are the three main sections:

Outer Ear (a)
The outer ear includes the auricle, the auditory canal and the eardrum. It funnels sounds from the surrounding environment into the hearing system. The auricle helps to gather the sound waves, and the auditory canal then directs them to the eardrum.

Middle Ear (b)
The middle ear is an air-filled cavity, which contains the smallest bones in the human body – the malleus, incus and stapes. These are connected to the eardrum on one side, and on the other side to a thin membrane-covered opening on the wall of the inner ear, the Oval Window. The middle ear is also connected to the throat via the Eustachian tube which keeps the air pressure in the middle ear equalized.

nner Ear (c)
In the inner ear the auditory input is processed by the cochlea, while information affecting balance is processed by the semicircular canals. Along the entire length of the fluid filled cochlea there are tiny hair cells. The hair cells are bent when the fluid is displaced by sound waves passed on by the middle ear bones. This triggers a chemical response, which activates the corresponding nerve endings. These then transmit the message to the area of the brain in charge of interpreting auditory input. Just an idea of how complex this organ is there are approximately 40 000 hair cells in a normal cochlea, which is the size of a pea!

Protecting Your Hearing

How does noise and loud sounds damage our hearing?

The ear is an amazing and complex organ, with delicate parts that are sensitive to the impact of loud sound. The inner ear consists of thousands of sensory cells that convert sound into nerve impulses so that the brain can understand the signal.  If these hair cells are exposed to very loud sounds they can be damaged or even destroyed, with hearing loss the result.

 

How loud is “too loud”?

We live in a noisy world.  On a daily basis we are exposed to sounds at work, home, school, sports, traffic, clubs, theatre, and concerts.  These can all be enjoyable experiences but when it is too loud it can become harmful.  The sound level scale developed by E-A-R research illustrates the typical sound levels we may experience and where it becomes harmful to our ears.  Normally 85dB is the level at which prolonged exposure can cause hearing loss, but the length of time/duration of exposure is also a significant factor.

 

How do I protect the hearing that I have?

We want to protect the hearing we’ve got, and there are many ways to do so:  earplugs, custom and non-custom (the famous yellow earplugs); earmuffs, musician plugs, HiFi earplugs and the list goes on!  Available in many bright coloured options they are easy to see and less likely to be lost.  In the work environment co-workers can also see when you are wearing noise protection. This tells them they need to get your attention first when trying to communicate!