Hearing loss – Definition
Hearing loss is a decreased ability to hear. There are two main categories of hearing loss:
- Conductive hearing loss due to something interfering with the sound passing to the inner ear.
- Sensorineural hearing loss due to damage to:
- The major organ in the ear responsible for hearing (the cochlea)
- The major nerve pathway (8th cranial nerve) and/or area of the brain responsible for hearing
Hearing loss – Causes
Causes of conductive hearing loss include:
- Impacted ear wax
- Fluid in the middle ear
- Ear infections
- Perforation of ear drum
- Stiff bones in the middle ear (otosclerosis)
- Loose or fractured bones in the middle ear
- Missing bones from the middle ear due to previous surgery
- Congenital anomaly causing complete closure of the ear canal (atresia)
Causes of sensorineural hearing loss include:
- Excess noise
- Family history
- Exposure to toxic substances, including such drugs as:
- Chemotherapy drugs
- Heart medicines
- Aspirin-containing drugs
- Acoustic neuroma
- Cardiovascular disease
- Multiple sclerosis
- Viruses ( measles, mumps, adenovirus, rubella)
- History of meningitis or syphilis
- Neurologic diseases such as multiple sclerosis and stroke
- Inner ear disorders such as Meniere’s disease
- Otosclerosis affecting the inner ear
- Previous brain or ear surgery causing damage to the inner ear
Hearing loss – Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
Risk factors for hearing loss include:
- Family history
- Meniere’s disease
- Not receiving all recommended immunizations
- Repeated or poorly treated ear infections
- Exposure to loud noise, music, or machinery
- Use of certain antibiotics and chemotherapy drugs
- Diseases that may result in blocked blood flow, including atherosclerosis, problems with blood clots, and collagen vascular diseases
Hearing loss – Symptoms
Symptoms may include:
- Decreased ability to hear any of the following:
- Higher pitched sounds
- Lower pitched sounds
- All sounds
- Speech when there is background noise
- Ringing sounds in the ears
- Problems with balance
- In children, hearing loss may cause difficulty learning to speak.
When Should I Call My Doctor?
Call your doctor if you notice hearing loss. You should especially call if you also have:
- Ear pain
- Ringing or other sounds in your ear
- Problems with speech or balance
- Sensitivity to sound
If you think you have an emergency, call for medical help right away.
Hearing loss – Diagnosis
The doctor will ask about your symptoms and medical history and perform a physical exam. Tests may include:
- Weber test — a tuning fork sounded and placed on your forehead or teeth. This can help distinguish conductive from sensorineural hearing loss.
- Rinne test — a tuning fork sounded and placed in front and then behind of the ear. This can help distinguish conductive from sensorineural hearing loss.
- Audiometric tests — These involve listening to tones in a soundproof room and reporting whether or not you hear the tones.
- Tympanometry — This test measures the pressure in the middle ear and examines the middle ear’s response to pressure waves.
- Computed tomography (CT) or magnetic resonance imaging (MRI) scan of the head — a type of imaging study that uses a computer to make pictures of the inside of the head. This may be done to check for a tumor or bone injury.
- Brain stem auditory evoked responses — electrodes attached to the scalp and used to measure the electrical response of the brain to sound
- Electrocochleography — This tests the cochlea and the auditory nerve.
Hearing loss – Treatment
This is probably the simplest, easiest treatment for hearing loss.
There are many types. Digital technology has created tiny devices that cause little distortion.
One example of a device is the FM trainer. With this device, a person speaks into a microphone. The sound is then transmitted by radio waves directly to the earphone set worn on your ear. This can be particularly helpful if you have trouble hearing speech when there is background noise. FM trainers can also help children with hearing loss to understand their teachers.
The cochlear implant is surgically implanted. It directly stimulates part of the brain and uses a tiny computer microprocessor to sort out incoming sound.
Treat Other Medical Illnesses
When hearing loss is caused by other medical conditions, it may be possible to improve hearing by treating those conditions.
Discontinue or Change Medications
If your hearing loss may be caused or worsened by a medication, talk to your doctor about stopping that particular drug or changing to a drug that does not affect hearing.
Address Nutritional Deficiencies
It may be possible to slow age-related hearing loss in elderly persons through dietary modification. For example, if you are deficient in folic acid, this supplement may be helpful for you. Talk to your doctor.
Surgery may be done in some cases of conductive hearing loss to correct the middle ear problem, such as in otosclerosis, ossicular damage or fixation, and ear infections.
If you have hearing loss, some changes may help you maximize your ability to hear. Follow these guidelines when talking to other people:
- Face the person that you are talking to. This will allow you to see their facial expressions and watch their lips move.
- Ask other people to speak loudly and more clearly.
- Turn off background noise (eg, TV, radio).
- In public places, choose a place to sit that is away from noise.
- Work with a special trainer to learn how to lip read. Lip reading involves paying close attention to how a person’s mouth and body are moving when they talk.
Hearing loss – Prevention
To help prevent hearing loss:
- Stop smoking.
- Adequately treat ear infections.
- Get all appropriate immunizations.
- Treat all medical conditions.
- Avoid exposure to excess noise.
- Use adequate ear protection when using noisy equipment.