Introductio to hearing loss and deafness
Hearing impairment, which means that there is either a partial loss in hearing or complete deafness, and it can be permanent or temporary. Sound is measured by its loudness or intensity (measured in units called decibels) and its frequency is measured in units called hertz. Hearing loss is described, depending on the slight, mild, moderate or severe levels of hearing intensities or frequencies and is associated with speech. Those whose hearing loss is more than 90 decibels are considered deaf.1
Hearing loss can occur at any age. Hence, the child is also unable to speak. With age, the chance of developing hearing loss is increased. Many people who are above 60 years of age could experience hearing impairment. A child with hearing loss does not have the ability to respond to auditory stimuli like speech. Hearing impairment affects the children’s learning process adversely.
1. Conductive Hearing Loss: This kind of hearing loss is caused when something interferes with the conduction of sound from outer ear to the middle ear.
2. Sensorineural Hearing Loss: This kind of hearing loss is caused when there is damage to the pathway, which carries the sound impulses from the inner ear to the auditory nerve and the brain.
3. Mixed Hearing Loss: This kind of hearing loss is a combination of both conductive and sensorineural hearing loss.
Causes of Conductive Hearing Loss
Causes of Sensorineural Hearing Loss
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Presbyacusis, a condition of hearing loss caused owing to increase in age and occurs owing to loss of hair cells in the cochlea.
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Injury caused by loud noise.
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Some viral and bacterial infections can damage the auditory nerve.
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Some powerful antibiotics can cause hearing loss.
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High doses of aspirin can cause constant ringing in the ears.
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Non-cancerous tumors like acoustics neuroma can also affect the auditory nerve leading to hearing loss.
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Neurological conditions like multiple sclerosis, stroke or brain tumor can cause hearing loss.
Diagnosis of hearing loss and deafness
Diagnosis is based on the clinical presentation, examination and diagnostic tests. The specialist may discuss the causes, which might be helpful in the treatment. A thorough physical examination is conducted. Some electronic devices and equipments are used to find out the degree of hearing loss.
The following are some of the hearing tests conducted to measure the degree of hearing loss.3
If the hearing loss is caused owing to brain abnormality, then magnetic resonance imaging (MRI) scan of the head may be helpful in diagnosis.
Written by: Healthplus24 team
Date last updated: April 15, 2012