What is deafness?
A general deafness definition is a condition of extreme hearing loss. Deaf people have very little hearing or no hearing at all. ASHA (American Speech-Language-Hearing Association) defines profound hearing loss as only being able to hear sounds greater than 90 decibels. This is about the sound level of a passing motorcycle, subway, or gas mower. Severe hearing loss ranges from 71-90 decibels before someone can hear sound. This equates to a vacuum cleaner or alarm clock.
Hearing is a complex process. It starts with sound waves entering the outer ear and traveling through the ear canal. They hit the eardrum, which vibrates in response. The resulting vibrations move through the middle ear to the inner ear. The inner ear houses specialized cells that translate the vibrations into electrical signals. The auditory nerve carries these signals to the brain. The brain interprets the signals as sound. A problem at any step in the process can cause the profound hearing loss of deafness.
The types of deafness can be classified in a few ways. Deafness can be congenital—present at birth or immediately afterwards—or acquired—showing up at any age later in life. Deafness can be unilateral—affecting one ear—or bilateral—affecting both ears. Deafness types can also fall into categories based on the affected part of the hearing process:
- Conductive hearing loss or deafness means sound can’t get through the outer and middle ear. If any hearing remains, sounds may be dramatically muffled or it may be difficult or impossible to hear soft sounds. Examples of conductive causes of deafness include infections and malformations of the outer or middle ear.
- Sensorineural hearing loss or deafness involves the inner ear or auditory nerve. This is the most common type of permanent hearing loss. Examples of sensorineural causes of deafness include trauma, malformations of the inner ear, and certain drugs and medical conditions.
- Mixed hearing loss or deafness is a combination of conductive and sensorineural problems.
Depending on the cause, deafness can happen suddenly or gradually over time. The risk of deafness increases with age, exposure to excessively loud noises, and illness that causes very high fevers. Genetics can also play a role in some cases.
Deafness causes difficulty understanding speech and hearing consonants. People with deafness may be able to hear some sound or the deafness may be complete. When some sound gets through, hearing aids or cochlear implants may be an option. Surgery may be an option for some types of hearing loss. Otherwise, deaf people rely on strategies such as lip reading, captioning, and sign language.
Sudden hearing loss either all at once or over a few days is a medical emergency. It usually affects one ear and is often noticed first thing in the morning. Seek immediate medical care if you have sudden hearing loss that may have other symptoms, such as a loud pop in the ear, dizziness, or ringing in the ears. Immediate treatment increases the chances of recovering some or all your hearing.
What are the symptoms of deafness?
Deafness is hearing loss that is generally profound. This means people aren’t able to hear sounds until they reach at least 90 decibels. However, the hearing loss of deafness can also be a complete inability to hear sounds.
Common symptoms of deafness
Common deafness symptoms and signs include:
- Asking people to speak louder or slower
- Difficulty hearing consonants or understanding words, especially in loud or crowded situations
- Hearing muffled sounds and speech
- Needing to increase the volume on TVs, radios, phones and other devices
These symptoms cause many people with hearing loss to withdraw from conversations and social interactions. This can lead to isolation and loneliness.
Signs of hearing loss in infants and young children are different than in older children and adults. Most babies receive a hearing screening shortly after or within one month of birth. When hearing loss develops in young children, signs of a problem include not following directions, speech delay, and turning up the volume on the TV or other digital devices.
Serious symptoms that might indicate a serious condition
In some cases, hearing loss can indicate a potentially serious condition. Seek immediate medical care (call 911) if you, or someone you are with, have sudden hearing loss with any of these serious symptoms including:
- Hearing loss upon awakening in the morning
- Loud popping sound followed by hearing loss
- Ringing in one or both ears
Sudden hearing loss strikes about 5,000 Americans each year. It usually affects people in their 40s and 50s. While it isn’t common, it is often treatable. Left untreated, only about 50% of people will recover some or all their hearing. Immediate treatment increases this number to 85%.
What causes deafness?
Deafness can result from problems with the outer or middle ear (conductive) or the inner ear or auditory nerve (sensorineural). In some cases, a mix of these problems causes deafness or hearing loss. These causes can be acquired during a person’s lifetime or present at birth or immediately afterwards. Some cases of deafness have no identifiable cause.
Conductive causes include:
- Tumors or foreign objects in the ear canal and even impacted earwax
- Fluid in the ear
- Infections, including those that cause very high fevers or that can be passed from mother to baby during pregnancy or birth
- Malformation of the outer or middle ear
- Perforated eardrum, which is a hole or tear in the eardrum
Sensorineural causes include:
- Diseases and illnesses, including viral infections, Meniere’s disease, and autoimmune diseases, such as Cogan’s syndrome
- Drugs that damage hearing, or ototoxic drugs, such as some antibiotics and cancer chemotherapy agents
- Exposure to loud noise
- Genetic syndromes, low birth weight, prematurity, or malformation of the inner ear
- Head trauma
- Presbycusis, which is age-related gradual hearing loss
What are the risk factors for deafness?
A number of factors increase can contribute to hearing loss and deafness. Risk factors for developing hearing loss or deafness include:
- Being exposed to short loud noises or prolonged high noise levels, including firearms, jet engines, concerts, loud music, power tools, and recreational vehicles, such as snowmobiles and motorcycles
- Having a genetic syndrome or inherited predisposition to hearing loss
- Taking ototoxic drugs
- Working in an occupation involving loud noise levels, such as carpentry, construction, farming or factory work
Reducing your risk of deafness
You may be able to lower your risk of hearing loss and deafness by:
- Following your doctor’s monitoring recommendations if you need an ototoxic drug
- Getting regular prenatal care for your unborn baby
- Protecting your ears during recreational and occupational activities that involve loud or sustained high noise levels
- Staying current with vaccination schedules
- Turning down the volume on personal devices that play music or audio
Having regular hearing exams is an important part of well-child care. It’s also vital for people with consistent or recurrent exposure to high noise levels. Identifying early signs of hearing loss allows you to take steps to help prevent progression of the problem.
How is deafness treated?
Treatment for deafness depends on the severity of the hearing loss and the underlying problem. Possible treatment options may include:
- Hearing aids may help when there is conductive hearing loss due to inner ear damage or sensorineural hearing loss from aging. They work by amplifying sound.
- Cochlear implants and bone-anchored hearing systems may help when conductive hearing loss is more severe, depending on the condition of the auditory nerve. These devices bypass the inner ear altogether and stimulate the auditory nerve. This means the auditory nerve must still function for these devices to be effective.
- Medications can treat some forms and causes of hearing loss. In particular, corticosteroids are often effective in treating sudden hearing loss when the cause is unknown.
- Surgery may be an option when conductive hearing loss is related to problems with the eardrum or bones of the inner ear.
What are the potential complications of deafness?
The main complications of hearing loss and deafness involve quality of life. Many people with deafness find that they avoid social interactions and conversations due to their disability. This, in turn, can lead to social isolation and loneliness, which can contribute to depression and anxiety.
Older adults with profound hearing loss may experience cognitive decline and memory problems. When deafness affects children, language development, learning, and academic performance can suffer. Research suggests that treating hearing loss when possible improves these problems.
Deafness can also have an economic impact when it affects a person’s ability to work.