HOW WE HEAR

We use the term hearing (or auditory) system to emphasise the fact that a range of mechanical and neural (nervous) mechanisms are involved, not just the part of the ear we can see.

 

Working from the outside inwards we first meet:

 

THE OUTER EAR:
The part we see, protects the eardrum and collects
Soundwaves

THE MIDDLE EAR:
It passes the sound from the eardrum to the inner ear.
Main function is to amplify sound

THE INNER EAR:
Converts the sound vibrations into electrical signals
which travel along the auditory nerve to the brain.
Sound is picked up by the outer ear and sent down
the ear canal to the eardrum. Sound vibrations cause
the eardrum to rock back and forth. Three tiny bones
in the middle ear send the sound vibrations to the
inner ear. Vibrations from the middle ear cause tiny
hair cells in the cochlea to move. These hair cells
are connected to the hearing nerve and send the hearing
signal to the brain.
 

 

Conductive Hearing loss:

Is a hearing loss resulting from a problem located in the outer or middle ear?

Cause
· Excessive earwax
· Damage to the eardrum
·  Ear infections

Fluid in the middle ear or stiffness in the bones of the middle ear

Symptoms
· Reduction in the volume of sound
· Inability to hear faint sounds
· Miss parts of words in conversations

 

Sensorineural Hearing loss:
Is a hearing loss caused by a damaged inner ear?

Cause
· Aging
· Noise exposure Hereditary factors
· Head injuries
· Medication that is toxic to the auditory system


Symptoms
· Reduction in the volume of sound
· Distortion in sound clarity
· Sensitivity to loud sound

 

Mixed Hearing loss:
It is also possible to have a conductive hearing loss and a sensorineural hearing loss at the same time.

Causes
· Damage in the outer or middle ear and in the cochlea or auditory nerve

TEST YOUR HEARING

· Do you have trouble hearing over the telephone

· Do you have trouble following conversation when two or more people are talking at the same time

· Do people complain that you turn the T.V volume too loud

· Do you miss hearing common sounds like the doorbell or telephone ringing

· Do you get confused about a direction a sound comes from

· Do you misunderstand some words in a sentence and need to ask people to repeat themselves

· Do you especially have trouble understanding the speech of women and children

· Do you have a history of working in a noisy environments

· Do you avoid social activities because you cannot hear well and fear you will reply improperly

· Do you experience ringing or buzzing sounds in your ears

· Do your family members or friends think you have a hearing problem

 

If you have answered yes to one or more of the above questions, you may have a hearing loss. The next step is to have a complete hearing evaluation by an Audiologist.

 

For further assistance, please contact the Hearing Centre, Monday to Friday 10am till 4pm.

 Acknowledgement: American Academy of Otolaryngology - Head and Neck Surgery Inc 1989