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
The Anatomy of the Ear
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:
- ]]>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
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
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 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.
- ]]>CT or 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.
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 doesn't 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. ]]>*¹]]> 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.
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.
American Academy of Otolaryngology–Head and Neck Surgery, Inc.
American Speech-Language-Hearing Association
Society of Rural Physicians of Canada
Ferri FF. Ferri's Clinical Advisor: Instant Diagnosis and Treatment. St. Louis, MO: Mosby; 2000.
Hansen MC. Otosclerosis and sensorineural hearing loss. A clinical study. Archives of Otolaryngology Head and Neck Surgery . 1983;109(9).
Lee SH, Chang Y, Lee JE, Cho JH. The values of diffusion tensor imaging and functional MRI in evaluating profound sensorineural hearing loss. Cochlear Implants International. 2004;149-152.
Marshall KG. Family Practice Sourcebook: Evidence-Based Emphasis . St. Louis, MO: Mosby; 2000.
Onion DK. The Little Black Book of Primary Care: Pearls and References. 3rd ed. Malden, MA: Blackwell Science; 1999.
Tierney LM, McPhee SJ, Papadakis MA. Current Medical Diagnosis and Treatment. 40th ed. New York, NY: Lange Medical Books/McGraw Hill; 2001.
¹ DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Durga J, Verhoef P, Anteunis L, Schouten E, Kok F. Effects of folic acid supplementation on hearing in older adults: a randomized, controlled trial. Ann Int Med. 2007;146(1):1-9.
Last reviewed September 2009 by ]]>Elie Edmond Rebeiz, MD, FACS]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.