Hearing Loss

Sound waves reach the structures inside your ear and the sound wave vibrations are converted into nerve signals that your brain recognizes as sound.

Your ear is divided into the outer ear, middle ear and inner ear. Sound waves pass through the outer ear and cause vibrations at the eardrum. The eardrum and three small bones of the middle ear amplify the vibrations as they travel to the inner ear. The vibrations pass through fluid in a structure in the inner ear called the cochlea. There are thousands of tiny hairs that are attached to nerve cells in the cochlea and these help translate sound vibrations into electrical signals that are transmitted to your brain.

• Up to 80 decibels is a safe range.
• From 80 to 120 decibels is in the ‘at risk’ range
• Above 120 decibels is in the ‘injury’ range.

There are prescribed levels of sound and durations that are safe for occupational exposure

Loss of hearing can occur gradually in older adults. Hearing loss may occur as the result of two defects as below:

• When sounds are unable to pass from your outer ear to your inner ear, often because of a blockage such as ear wax or a build-up of fluid from an ear infection that interferes with the movement of the ossicles and eardrum (otitis media) or because of a perforated ear drum
• When the sound is not picked up due to damage to the sensitive hair cells inside the inner ear or damage to the auditory nerve; this may occur with age or as a result of trauma. Persistent exposure to loud noise plays a role in this type of hearing loss.

It may be as a result of a combination of the above causes. Developmental malformation of the outer ear, ear canal, or middle ear structures could contribute to hearing loss as well.
Drugs, such as the antibiotic gentamicin and certain chemotherapy drugs, can damage the inner ear.  Some illnesses that result in high fever, such as meningitis, may damage the cochlea

The following symptoms may indicate that you have a problem with hearing loss:

• Difficulty in following conversations words and missing parts of it needing to ask the person to repeat himself/herself.
• Ringing, buzzing or whistling sound in the affected ear
• Speaking in a louder tone than required
• Listening to music or the TV at a higher than required volume

Hearing loss causes the person to feel distressed as they face increasing difficulty in communication. It is important to initiate treatment as many conditions will respond to specific treatment.

Clinical examination: Your doctor will check your ears for infection or earwax as well as for any structural causes of your hearing problems.
Tuning fork tests.Tuning forks are two-pronged, metal instruments that produce sounds when struck. These tests will help distinguish between hearing loss from damage to the conducting parts of the ear including your eardrum and damage to the nerves of your inner ear or damage to both.
Audiometer tests.These are conducted by an audiologist. You will be presented a range of sounds of various tones one ear at a time and you will be asked to indicate when you hear it.

• Your physician will treat you based on the underlying cause of hearing loss.
• Antibiotics are prescribed for infections.
• Ear drops or ear irrigation will help resolve blockage by ear wax.
• Hearing aids help with hearing by amplifying the sounds that are picked up by the inner ear.
• Surgery is performed to correct any defect in the ear.

There are four major types of surgeries to correct a problem with your hearing. Your surgeon will choose the most suitable surgical procedure depending on the cause of hearing loss.
Myringotomy: Is a procedure to create a surgical incision in the eardrum to remove a collection of fluid behind the eardrum that may be the result of a middle ear infection (otitis media).
Tympanoplasty: This is the surgical repair of the perforated eardrum that may have occurred as the result of trauma or infection. An incision is made into the ear canal. Your surgeon will remove the perforated part and insert a graft into the eardrum. The eardrum is folded back to close the perforation.
Stapedectomy: replaces the diseased stapes bone with a prosthetic device.
Cochlear implants: It uses a tiny electronic device that directly stimulates the auditory nerve to perceive sound. These implants consist of two sections, internal and external. The inner section is inserted into the ear during the surgery bypassing the damaged hair cells. Then, the external section is attached to the internal section using a coil and magnet.

You need to make plans for the post-surgical care and recovery, to get adequate rest after the procedure, and find someone who can assist in your day-to-day tasks.

• You will have all your blood tests reviewed by your anaesthetist who will meet you before the procedure.
• You will be asked to sign a consent form for surgery and anaesthesia. At this point you should clear up any doubts about the procedure.
• You should not eat or drink anything for at least 8 hours before the procedure (from midnight on the night before) and have only a light meal. Follow your doctor’s advice on any pre procedure preparation.
• You should quit smoking for 6 to 8 weeks before the surgery. Smoking may cause breathing problems during and after the procedure and also can slow down the recovery process.
• Medications such as ibuprofen or aspirin may increase the risk of bleeding. So, check with your doctor so that you stop it if possible.
• If you have an infection such as a flu or cold, inform your doctor.

For the first few weeks post-surgery, you should follow the advice of your doctor with respect to activities to avoid and precautions to take.
In the immediate postoperative period call your doctor if you feel very dizzy and it doesn’t settle, if you develop a fever over 38 ̊C or have a persistent discharge or  have a ringing sensation in your ears that doesn’t settle.

• Protect your ears from workplace related sound. Specially designed earmuffs can bring sounds to an acceptable level. Consider regular hearing tests if you work in a noisy environment. Regular testing of your hearing can provide early detection of hearing loss.
• Avoid recreational exposure to sound at high decibels:  Listening to loud music for long periods of time, can damage your hearing. Wear hearing protectors or take breaks from the noise during loud concerts to protect your ears. Turning down the volume when listening to music can help you avoid damage to your hearing.