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
Causes of conductive hearing loss include:
- Impacted ear wax
- Fluid in the middle ear
- Perforation of ear drum
- Stiff bones in the middle ear (otosclerosis)
Causes of sensorineural hearing loss include:
- Excess noise
- 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
A risk factor is something that increases your chance of getting a disease or condition.
Risk factors for hearing loss include:
- 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
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
The doctor will ask about your symptoms and medical history, and perform a physical exam. Tests may include:
Weber Test–a tuning fork is sounded and placed on your forehead or teeth. This can help distinguish conductive from sensorineural hearing loss.
Rinne Test–a tuning fork is 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 you hear them or not.
Tympanometry–measures the pressure in the middle ear and examines the middle ear's response to pressure waves.
CT Scan of the Head–a type of x-ray 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 are attached to the scalp and used to measure the electrical response of the brain to sound.
Electrocochleography–tests the cochlea and auditory nerve.
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 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.
This device is surgically implanted. It directly stimulates part of the brain, and uses a tiny computer microprocessor to sort out incoming sound.
Treating Other Medical Illnesses
When hearing loss is caused by other medical conditions, it may be possible to improve hearing by treating those conditions.
Discontinuing or Changing 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 doesn't affect hearing.
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