To understand how we lose our hearing it is necessary to understand how we hear in the first place. Contrary to what most people think we hear with our brains rather than our ears, and there are two distinct pathways that produce the sensation of hearing.

Air conduction

For air conduction to take place the sound waves travel through the air and into your ear canal. When the sound waves hit the tympanic membrane (the eardrum) it causes it to vibrate. The tympanic membrane is connected to the three smallest bones in the body, the malleus, the incus, and the stapes. The vibration of the tympanic membrane transfers this movement to those three bones which in turn vibrates a membrane attached to the inner ear.

The cochlea (the inner ear) is a fluid filled cavity containing multiple tiny hair cells which send nerve impulses up to the brain when triggered by the movement of fluid in the cochlea caused by the vibrations. Different frequencies of sound stimulate different hair cells and this is how we differentiate different pitches of sound, resulting in our sensation of hearing.

Bone conduction

Sound can also be transmitted by bone conduction. If sound vibrates against the skull bone, these sound vibrations can transfer directly through to the cochlea rather than the conventional route down the ear canal and via the middle ear. You could think of bone conduction hearing as a shortcut, bypassing the outer and middle ear as it does.

As there are two types of hearing there are two types of hearing loss

Conductive hearing loss

Conductive hearing loss occurs when the sound waves can't actually get to the inner ear. Generally this has three main causes, the ear is blocked with excessive wax, an accident has caused damage to the tympanic membrane, or the three bones are not functioning properly. If the cause of conductive loss is excessive wax build up, this is the easiest type of hearing problem to fix with ear syringing. Once the obstruction has been removed normally hearing resumes. Antibiotics can sometimes be used for infections which have caused a temporary conductive hearing loss.

Sensori-neural hearing loss

Sensori-neural Hearing loss occurs when the nerves or the hair cells that sense sound waves have been damaged. The most common way that this happens is quite simply the ageing process, followed by noise induced hearing loss. Other factors can cause this type of loss too, such as hereditary factors, drugs etc Certain antibiotics can damage the nerves which are involved with hearing; these include diuretics, anti-inflammatories such as aspirin or ibuprofen, as well as some drugs used to treat cancer. In fact any drugs taken can have an effect on your hearing, the term is ototoxixty. If unsure you should always consult a medical professional.

Vascular diseases which causes Sensorineural Hearing loss include sickle cell disease and diseases in which excessive blood clotting occurs. Sufferers of leukemia, diabetes, kidney problems also have an increased risk. Many common infections such as influenza, herpes simplex and zoster, mumps measles and meningitis can lead to hearing loss.

In some cases hearing loss is unavoidable but with a little bit of care you can ensure that you keep hold of your hearing for as long as possible.