Hearing is one of our special senses and the disability of not being able to hear can be a significant one. Typically hearing loss can be divided into the paediatric population and the adult population. It can also be looked at as to what type of hearing loss it is. A conductive hearing loss is where the deficit lies anywhere from the external ear, through the canal, eardrum and the small bones of the middle ear (ossicles) that transmit the sound wave to the inner ear. A sensorineural hearing loss is related to damage to the inner ear or the nerves that transmit the sensation of sound to the brain.
It is very important when seeing someone for hearing loss a thorough history and examination is undertaken as part of the ENT consultation. This allows the surgeon to distinguish between different hearing losses and choose the most appropriate investigations.
Paediatric Hearing loss
This is by far the commonest cause of a hearing loss in children. Fluid that develops and stays behind the eardrum causes a problem with the conduction of sound. Children present in a variety of forms such as simple inability to hear, the volume of the television increases, however more subtle changes in behavior speech development and poorer academic performances can be related to the fluid collection. This fluid can be seen on examination of the eardrums.
Glue ear per se will not damage your childs ears, however if it is affecting your child significantly for a continuous period of over 3 months and there is a defecit in hearing then it is reasonable to consider treatment of the glue ear.
Surgical intervention in the form of a grommet insertion +/- adenoidectomy is a common and very successful procedure to improve the ability of your child to hear.
Sensorineural Hearing loss in children
Thankfully this is significantly less common than glue ear. A range of severity exists and profound hearing losses should now be screened for at birth in the form of one of two simple, painless hearing tests (otoacoustic emissions or an automated brain stem response). If this is found then a child should be put through a specialist audiological service to offer maximal aiding in the first instance and possibly further surgical input to improve the patients hearing ability.
Adult Hearing Loss
This is a large group of hearing losses that must be managed by taking a full, history, examining the patient and undertaking appropriate special investigations. A few of the common and interesting causes of adult hearing losses are outlined below.
Wax in the Ear Canal
Something as simple as wax, can occlude the ear canal and cause obstruction to the transmission of sound. This especially happens when patients have a tendency to use cotton buds in their ears and inadvertently push the wax to impact deep in the ear canal.
Wax is a physiological substance that confers bacteriostatic and waterproofing abilities to the ear canal. Small volumes of wax show a healthy ear canal. If larger quantities exist and obstruction and hearing loss ensue then microsuction can be undertaken to clear the wax from the ear canal and improve the hearing rapidly.
With age there is a gradual decrease in the function of the organ of hearing, the cochlea. This presents itself with a progressive hearing loss. The higher frequencies are affected the most and hearing worsens with time. It is an exceptionally troublesome symptom but can be helped in different ways.
Hearing aids have improved dramatically over the past few years. Introduction of new digital technology and reduction of size of hardware has brought hearing aids into a new dimension. Hearing aids can significantly improve the quality of an individual’s life offering them discreet but significant amplification that can assist them in the ability to hear.
This is a hereditary condition where the small bones (ossicles) that transmit sound become fixed. Typically the smallest bone, the stapes, is the one that becomes fixed and causes the problem. Patients are affected with a progressive hearing loss in adulthood and more females are affected than males often during / after their pregnancy.
The problem is progressive and a number of treatment options exist. A hearing aid is a safe option and involves no surgery and no risk to the patients hearing. A stapedectomy is the classical operation to remove part of the fixed bone and replace it with a prosthetic replacement. This operation has a good chance of success. The significant downside to the operation is the very small risk of complete hearing loss. One final treatment option includes a bone anchored hearing aid which involves a surgical operation to fix a screw that integrates with the skull bone and then a hearing aid may be attached to it. This is not the classical operation for this condition but may be considered.
Sudden Sensorineural hearing loss
Very rarely a patient may have a sudden loss of their hearing. It is important to clarify this with regards to if it is just a conduction of sound deficit or is it due to an inner ear and more serious pathology. The reason is if it is a sudden sensorineural hearing loss (inner ear related) most ENT surgeons commence some medical intervention rapidly, typically in the form of steroids. Occasionally some use antiviral treatments. The use of these interventions is not scientific but if it is to be given it should be done so as early as possible.
Importantly, if a person does suffer with a sudden sensorineural hearing loss then an MRI will have to be performed as an investigation (MRI see below) in order to exclude a rare cause of this phenomenon which is a benign nerve sheath tumour called an acoustic neuroma.
MRI of the inner ear
Hearing loss is a disability that can often be helped either surgically or with the intervention of hearing aids. The use of aids should not be discouraged and should be likened to the use of spectacles for a visual disability. Hearing is crucial to integration into normal social interaction and therefore should not be underestimated and should be addressed rapidly from the very youngest to the oldest in the population.