Hearing loss is something which everyone is aware of. But to describe it in brief it is the process that occurs when the sound waves in the surroundings reach the structures inside our ear and the sound wave vibrations are converted into signals and are then recognized by the brain as sound.
In this article, we discuss the different types of hearing loss:
- Sensorineural Hearing Loss
- Sudden Hearing Loss
- Conductive Hearing Loss
- Sudden Sensorineural Hearing Loss
- Mixed Hearing Loss
- Noise Induced Hearing Loss
- High Frequency Hearing Loss
- Low Frequency Hearing Loss
- Central Hearing Loss
The problem of hearing loss is the most banal disorder in people these days all over the world.
Hearing loss is described as the complete or partial inability to hear sounds in one or both ears.
Mostly aging is one of the main causes for hearing loss. It is also called presbycusis which is gradual loss in hearing in people while aging. Hearing loss generally starts with loss in hearing and ends up in complete deafness if not given a proper medical treatment.
Gradual buildup of the wax in the ears blocks the ear canal and tears the hair on the nerve cells which send the signals to the brain and convert the vibrations into sound. The blockage caused due to the earwax in the ears is a cause of hearing loss in almost all age groups.
However in most cases the damage caused to the inner ear is also the reason for decreased ability to hear. Prolonged exposure to noise and beyond a certain limit is also a reason for loss in hearing.
Aging is also one of the major reasons which cause hearing loss. All this lead to damage to the hair on the nerve cells which stops the transmission of the signals to the brain and its conversion to sound.
Ear infections, ruptured eardrums, tumors and bone growths in the inner or outer ear also lead to hearing loss. According to a study in US the evidences says that lack of Vitamin B is also one of the reasons for the disease. Minor hearing diseases are common after 20 yrs.
All the newborn babies often go through a screening for hearing loss. Hearing loss in children may cause slow development of speech in them.
Ear hygiene is a must for newborn babies and children. The fluid and the ear wax accumulate following substantial hearing problems with infections in the ear.
Fluid in the ear that remains for more than 8- 10 weeks is a cause of concern and should be treated immediately.
The risk factors for the babies include family history of the disease which can be hereditary, low body weight of the baby, improper development of the bones and nerves in the ear structure and some infections due to the viruses and bacteria.
The symptoms of the diseases include difficulty in understanding what others are speaking specially in a crowded place, subdued quality of speech as well as other sounds, periodically asking others to speak loudly and clearly, the need to increase the volume of television and repudiation from a conversation.
If anyone shows such symptoms he/she should immediately consult an ENT specialist and take a proper medical treatment rather than ignoring it.
No one can’t antipode the different types of hearing loss but can prevent it so that you don’t have to live in a world of silence and less audible sounds.
Sudden Hearing Loss
Sudden Hearing Loss is defined as a hearing decline in 72 hours or less, resulting in a 30dB hearing reduction, and over at least 3 separate frequencies. The majority of the time, the hearing loss does not occur all at once, but over a period of a few hours.
According to a recent estimate, approximately 20 out of every 100,000 people will be affected by a sudden loss in hearing. Sudden hearing loss is usually unilateral (meaning it only occurs in one ear), although bilateral SHL is not uncommon.
Sudden Hearing Loss Symptoms
Besides the obvious of a decrease in hearing, SHL sufferers frequently experience:
- This occurs in approximately 20% -60% of patients.
- Tinnitus, or ringing of the ears, is often another symptom of SHL
People who experience sudden hearing loss in one ear have a much higher risk of experiencing it in the other ear as well. The worst part is that SHL can become permanent.
Sudden Hearing Loss Causes
- Endocrine Disorders
- Adrenal Function: When the adrenals stop working properly and producing the proper hormones, SHL can occur
- Unknown (idiopathic): In 85 per cent of cases of sudden hearing loss the cause is unknown. These cases are referred to as idiopathic. In the majority, the hearing is affected in only one ear (unilateral).
- Noise: Sudden hearing loss may occur from exposure to excessively loud noises (noise induced hearing loss), for example from blast injuries (from a nearby explosion) or from firearms or fireworks, especially in enclosed spaces.
- Infection: As middle ear infection or accumulation of fluid behind the tympanic membrane (eardrum) can also occur rapidly, causing a temporary conductive hearing loss. These cases are referred to as idiopathic. Also, meningitis is one of the commonest causes of severe or profound acquired deafness in babies and children. Measles and mumps are also associated with sudden hearing loss.
- Head injuries: Head injuries, especially those associated with a fractured skull, may produce profound and often permanent hearing loss.
- Surgery: Sudden hearing loss may occur after any surgical procedure on the ear, and the degree of risk depends on many factors. The hearing loss may occur immediately, in the few days following the operation, or even many years later.
- Barotrauma: Barotrauma may occur when the ear is exposed to sudden pressure changes, possible when flying or diving. Most commonly, the middle ear is affected, causing a sudden hearing loss.
- Medications: Some Medications can cause SHL such as some antibiotics, chemotherapy, or anti-inflammatory drugs.
What should you do if you lose your hearing suddenly?
As a sudden hearing loss can return to normal or near normal in some cases, it may be tempting to adopt a ‘wait-and-see’ policy. However, if the problem persists or you think you have a sudden hearing loss in one or both ears, you should be seen by a specialist as soon as possible. You should go to your GP (family doctor) and ask for an urgent referral to an ear, nose and throat (ENT) specialist.
Sensorineural Hearing Loss
Sensorineural hearing loss, also sometimes known as nerve-related hearing loss or sensory hearing loss, is caused by damage to the inner ear nerves. This damage causes poor hair cell function, which in turn makes it difficult for sound messages to be transferred from the hair cells, through the nerves, and to the brain for processing to create meaning. Sensory hearing loss can be caused by a large variety of factors including:
- The Aging process
- Over exposure to loud noises
- Possible problems from birth
- Bad infections or fevers
- Head trauma
- Harmful medications (oxotoxic)
- Chemotherapy for cancers
Types of Sensorineural hearing loss
Sensorineural hearing loss includes two types of hearing loss:
Sensory hearing loss: This occurs when the cochlea or the tiny hair cells in the ear are badly damaged
Neural hearing loss: This is experienced when damage occurs to the hearing nerve or the part of the brain responsible for hearing. This problem can impede proper information processing and transmission by the nerves to the brain.
These types of sensorineural hearing loss can not only make hearing faint sounds difficult, but it can even make the ability to understand speech or to hear things clearly incredibly difficult. It can also interfere with certain frequencies more then others.
Detailed causes of sensorineural hearing loss
The origin of this type of hearing loss, besides the most common reason of noise exposure, is thought to be:
- Pre-birth (possible infection in the fetus)
- Perinatal (occurs during actual birth when complications arrise)
- Cancer treatments such as
- Chemotherapy: The most known types of chemotherapy that lead to hearing loss are the platinum drugs or compounds. Common names include Cisplatin and Carboplatin.
- Radiation: Radiation may damage the hair cells, much like chemotherapy. Radiation may also destroy the area of the brain that converts sound into meaning or the nerves that convey electronic signals between the hair cells and the brain.
- Unknown causes
What are the symptoms of sensorineural hearing loss?
Symptoms of hearing loss may include:
- Tinkling or ringing or sounds in the ear
- Difficulty hearing in the presence of background noises
- Not paying attention to sounds (such as voices, environmental noises)
Is sensorineural hearing loss reversible?
In a word. No. At least not in the sense that you are probably thinking. Sensorineural hearing loss generally results in permanent hair cell damage. Can Sensory hearing loss be treated with great success: YES! Please read on.
Scientific advancements in stem cell research are showing great promise in the area of hearing loss. One day, scientists might be able to re-grow new hair cells that can be successfully implanted in those with hearing problems.
Sudden Sensorineural hearing loss
Sudden Sensorineural Hearing Loss ( SSHL ) is defined as a hearing loss of at least 30 dB at three frequencies that are connected, occurring over a period up to three days, many times even within hours. The majority of the time only one ear is effected and may be first noticed upon waking or when using the affected ear alone, as when on the phone. A popping sound may accompany the sudden loss, sometimes even experiencing vertigo and tinnitus.
Every year, SSHL affects up to 1 in 5000 people, or up to 60000 a year in the United States alone. Sudden Sensorineural hearing loss most often occurs in adults aged 30-60, although it happens in children and older adults as well.
Getting to Know Sudden Sensorineural Hearing Loss
Sudden sensorineural hearing loss (SSHL) is a medical condition described as a rapid loss of hearing and is also commonly referred to as sudden deafness. Determining exactly what causes sudden deafness and which treatments are most effective is still a work in progress.
This medical condition can come on suddenly with no warning or progress over a period of about three days. Doctors consider this type of condition a medical emergency and advise anyone suffering from it to seek medical attention as soon as possible.
Though cause and treatment of SSHL have yet to be precisely established, doctors can definitively determine whether or not a person is suffering from the condition. A simple, normal hearing test is administered by measuring sound in decibels and frequency. A person with normal hearing hears at about 60 decibels. Someone with SSHL hears at 30 decibels.
Frequency measures sound waves and is what helps us to differentiate one sound from the next. Most people with SSHL are only affected by the condition in one ear, so hearing is still possible, but not as clear. Statistics show this is true in 9 out of 10 people.
There are two instances in which the person being affected first notices SSHL. In the first instance, people hear a loud buzz or popping in the ear immediately before deafness occurs.
The second instance usually involves the person waking with a loss of hearing or noticing it for the first time while trying to initiate a phone call. Most experience some dizziness or ringing in the ear prior to losing hearing.
Many patients never know exactly what caused their sudden sensorineural hearing loss. There are over 100 possible causes of sudden sensorineural hearing loss and seldom is a specific cause identified.
According to a majority of doctors, roughly 10 – 15% of those suffering with SSHL know the definitive cause of their condition. For the other percentage of patients, diagnosis is usually based on their medical history.
What causes SSHL varies. In some cases, the condition has been linked to Menieres disease or other similar disorders. Multiple sclerosis and similar neurological disorders correlate to SSHL as well as immunologic diseases (i.e. Cogan’s syndrome).
Other possible causes include infectious diseases, trauma sustained to the body including the head, circulatory issues and abnormal tissue growth. Some SSHL cases are associated with toxic or drug-related causes such as snakebites and ototoxic drugs that are harmful to the ear. Sudden deafness has also been attributed to some viral infections and autoimmune disease.
Researchers are working on the theory that hearing loss may be attributed to a lack of blood flow in the ear as well as poor air flow. This theory is based on the thought that if the inner ear does not receive a healthy dose of oxygen or blood flow, hearing becomes impaired or is blocked all together.
The best sudden sensorineural hearing loss treatment begins at the first sign hearing has been lost. Chances of recovering from SSHL are greatly influenced by how quickly treatment begins.
Patients are not encouraged to wait and see if their hearing will return on its own. This can lessen the chance of ever hearing out of that ear again.
Presbycusis: Age-Related Hearing Loss and Treatment
What is presbycusis?
Presbycusis is the most frequent type of hearing loss affecting the modern world. It is considered to be a slowly declining loss of hearing that occurs in some adults as they age.
Presbycusis, or age-related hearing loss, is often first noticed when attempting to hear higher frequencies. It can start as early as age eighteen and occurs more often in men then in women. Hearing higher pitches, such as a child’s voice or the telephone ringing, is usually effected most by presbycusis, and it most often affects both ears rather than just one.
Presbycusis is very common, but sometimes hard to define. The definition of presbycusis changes with each individual. It is estimated that thirty-five percent of those between sixty-five and seventy-five suffer from this type of hearing loss. It is also estimated that forty to fifty percent of people over the age of seventy-five suffer from presbycusis hearing loss symptoms.
Because the onset of presbycusis occurs slowly over time, many sufferers often do not realize that they have it at first, or at all. Communications may sound muffled, and it may become extremely hard to hear people speaking in crowds. Ringing or buzzing in the ears can also indicate hearing loss (accompanied by tinnitus).
Changes in the ear can be contributed to one of the causes of presbycusis. The inner ear changes as a person grows older or even changes in the middle ear; affecting the nerve that lead up to the brain. Because the changes in the ear and subsequent hearing loss are so gradual, people often don’t even notice that a loss of hearing has occurred until the presbycusis is quite advanced.
One of the main causes of presbycusis is environmental noise. Daily exposure to certain types of loud sounds such as music, construction work, or firearms can be a contributing factor. Presbycusis symptoms can also be a heredity condition and can be present from an early age. Doctors will often look at medical records and family history to assist in the diagnosis of presbycusis causes.
Diet and dietary conditions, including diabetes have also been linked to presbycusis. Diets high in saturated fats have been associated to accelerating the problems with the cochlea, the auditory part of the inner ear.
Diabetes has shown links to affecting the blood vessels in the cochlea, which reduces the blood supply which has been shown to directly relate to hearing loss.
Changing one’s diet can be a key contribution to avoiding the onset of presbycusis. High diet with a sufficient supply of omega-3 fatty acids has been shown to substantially decrease the risk of hearing loss. Smoking also plays a major role in presbycusis.
Smoking affects the blood vessels all over the body, including in the cochlea, making one more susceptible to age-related hearing loss. Frequent use aspirin and other over-the-counter drugs also seem to affect the onset of presbycusis.
This type of hearing loss can be prevented by being aware of the loud noises that can damage the ear and result in permanent loss of hearing. It is important to wear ear plugs when using loud machinery such as lawn mowers, fire arms and other loud appliances.
There are also ear muffs that have been filled with a special fluid that can help protect the ears from being damaged from these and other loud noises. Music in bars and nightclubs, which often cause people to hear a ringing in the ear (or tinnitus) after visiting them, is a sign that the hearing is being affected.
Even though loud noises are not often completely avoided, the time around those noises can be cut down. When listening to music or watching the television, it is important that the sound is turned down to a reasonable level. Presbycusis and tinnitus frequently go hand in hand as a result of these overly-loud noises.
There are other presbycusis treatments available. Learning to use speech-reading is one possible treatment for presbycusis. Speech-reading is the use of visual cues so that the patient can determine what is being spoken. Although it is not the typical “medicine”, this can still help those with the condition participate more normally in conversations.
Once the symptoms of presbycusis become apparent, it is important to seek medical attention, and possibly get an audiogram to determine the extent of the hearing loss.
Conductive Hearing Loss
Introduction to conductive hearing loss
Conductive hearing loss is a type of hearing loss due to abnormalities in mobile portions of the ear. These are the movable parts (including the eardrum) that conveys sound from the outside to the inner ear where the nervous system takes over and sends signals to the brain. Conductive hearing loss occurs when these movable parts are damaged or when their mobility is impaired. Conductive hearing loss is the most popular cause of hearing impairment- especially in kids.
Differentiating between different types of hearing loss
The form of hearing loss that happens depends on which part of the ear is not acting properly. For instance, if there is something not operating in the ear canal, eardrum, middle ear bones or middle ear space (e.g. fluid), it may result in a conductive hearing loss (sometimes called “mechanical hearing loss”). Consequently, sound waves cannot be conducted to the inner ear.
On the other hand, if something is not working in the auditory nerve, brain or cochlea, it more commonly ends up in a sensorineural hearing loss (also called “nerve hearing loss”).
Causes of conductive hearing loss
Conductive hearing loss is caused by a blockage that prevents the conduction of sound from the outer to inner ear. This blockage can be due to one of the following reasons:
- Infection: The most common cause of conductive hearing loss is fluid in the middle ear. This may be a result of repeated or chronic infection (otitis media).
- Injury of the outer ear: Holes in the eardrum (tympanic membrane perforation) and skin cysts (cholesteatoma)
- Blockage of the ear canal: It may develop as a result of eustachian tube obstruction (eg, due to allergies) or due to excessive ear wax that plugs the ear canal or other small objects like food, beads or insects. Narrowing of the ear canal can also be due to surgery or disease.
- Otosclerosis: It is a condition in which the ossicles of the middle ear become immobile and hence there is a defect in the proper conduction of sound through the middle ear, leading to conductive hearing loss.
- Congenital (in-born) deformities: e.g., Down syndrome, Franceschetti Syndrome, Treacher Collins Syndrome or Achondroplasia (dwarfism)
Treatment of conductive hearing loss
Because conductive hearing loss is not caused by nerve damage, as is the case with sensorineural loss, it usually is treatable by removing the blockage and almost all conductive hearing loss is transitory or temporary and can be remedied with hearing returning to normal levels. Hearing aids are generally not needed. (insert link over hearing aids to “hearing aid reviews” page)
Therefore, treatment essentially depends upon removal of the cause. Foreign objects must be removed.
Ear infections and ear fluids generally demand medical examination and treatment, though some fluid conditions are self-healing and transitory.
Ear wax should be extracted only by someone with proper experience and safe instruments. Ear infections, such as otitis media can be treated with oral antibiotics or eardrops. In some cases, fluid behind the eardrum can be drained by inserting pressure-equalizing tympanotomy tubes through the eardrum, a procedure commonly known as “tubes in the ears.” Ruptured eardrums also can be treated with antibiotics or surgery if necessary.
Noise Induced Hearing Loss: What it is and how to treat it
The sound of a baby crying, a dog barking, or the evening news are all noises we hear through the day without giving it much thought.
People who are living with noise induced hearing loss (NIHL) understand just how important your sense of hearing is. These people have either partial or total loss of hearing, and dealing with this can be very difficult.
It is estimated that about fifteen percent of the people living in the United States are dealing with NIHL. There are many reasons that hearing loss occurs and many ways that you can prevent this irreparable damage from being done, before it is too late.
All sound can be measured based on how strong or loud a noise it makes. Sound level is ranked based on the measurement of units called decibels. The higher the decibel is the louder the sound. Basic sounds that we hear every day, like normal conversation have a decibel level of around 60, which is an acceptable level for most people.
When sounds rank at a decibel level of over 85, this can cause a problem with your hearing. When sounds are continuously heard at this level over an extended period of time, hearing damage can be done.
Damage can also be done with just one singular exposure to a loud sound. A sound louder than 120 decibels, such as the sound of an explosion or a firecracker, instant hearing loss can occur.
There are tiny hair cells that are found on the inside part of your ear. These hair cells are sensory cells that transfer the sound you hear into a signal to the brain telling it that a sound has been heard. When these hair cells are damaged, hearing loss can happen.
Unfortunately, once the hair cells are damaged there is no repair that can be done to fix it. Sometimes hearing loss can be temporary, which is referred to as temporary threshold shift, which only lasts for between sixteen and forty-eight hours. All other types of noise induced hearing loss are permanent.
There are many causes of noise induced hearing loss. They can be split into two categories. If the hearing loss was caused by one-time exposure than the noise you were exposed to would be a very loud noise.
These noises include things like a firearm, dynamite, or an explosion and you would need to be relatively close to the noise to have it damage your ear. If the hearing loss was caused by exposure to loud noises over an extended period of time, the sound would not be quite as loud – but still too loud.
These noises include things like power machines, chainsaws or loud music and are sounds that are heard during an extensive timeframe. This type of hearing loss is the most preventable.
Some people who have hearing loss are not even aware that they suffer from this condition. One of the first signs that you can look for as a warning that you might be starting to have a hearing loss, is having trouble hearing what people are saying to you.
You may hear that they are talking and understand most of what they say but you still have trouble hearing all of the words that are spoken.
Another sign is that sounds around you start to be distorted or muffled and you are just not hearing them like you know you should. If you start to notice these symptoms you should immediately contact your doctor who can give you a hearing test to check.
Prevention is the key when it comes to hearing loss, and it is crucial to know that hearing loss is 100% preventable. Since the injury cannot be repaired it is vital that you prevent the damage from happening in the first place.
First, you should educate yourself on what kinds of noises are damaging and what noises are normal. This will help you know when you need protection for your ears.
When you are going to be exposed to loud noises over a long duration, you should always wear earplugs in your ears. Earplugs are specifically designed to protect your ear from the damage that loud noises can cause.
High Frequency Hearing Loss: What it is and how to treat it
High frequency hearing loss is exactly what the name suggests; it’s when a person can no longer hear high frequencies. Almost everything known to us as human beings has a frequency, including the Earth spinning around on its axis. Hearing, for example, has its own frequency.
People, who can hear normally and without the help of a hearing aid, typically hear between 20 Hz to 20,000 Hz. Hz, or Hertz, is the unit used to measure frequency. High frequency sounds range from 3,000 to 6,000 Hz, an example being vibrations. To understand what something with a frequency of 50 Hz sounds like, imagine the low rumbling of thunder from a storm approaching in the distance.
A person who loses the ability to hear high frequencies is typically suffering from an impairment of the inner ear. This type of hearing loss is generally associated with over exposure to high frequency noise.. Hearing loss due to over exposure is preventable.
Hearing loss is associated with both occupational and recreational activities. To prevent damage to the inner ear, wear ear protection when working around high frequency noises like sirens, firearms, and power tools.
For recreational purposes, listen to music at normal volumes and wear ear protection when using firearms, motorcycles, and snowmobiles.
The intensity to which you are exposed to noise as well as frequency determines how much damage you are causing to your inner ear. Intensity refers to loudness and frequency refers to pitch. Damage to the inner ear is possible because humans are sensitive to sounds played at high frequencies.
High frequency hearing loss results when hair cells of the basilar membrane within the cochlea die. Sound is transferred from the hair cells through the nerves and to the brain where it is processed.
When the hair cells become damaged and die off, hearing is significantly impaired or lost all together. There are many contributing factors that can cause a person to lose the ability to hear high frequencies.
Old age is one of the most common contributions to this type of hearing loss. Half of people over the age of 75 suffer from hearing loss. As the human body ages, hair cells, which are part of the hearing process inside the ear, naturally break down and die.
When this happens, it becomes harder to hear in noisy areas. Some sounds appear louder than others. Sounds that are high in pitch, like “s” and “th,” are difficult to distinguish. People’s voices sound muffled. Men’s voices are easier to hear than women’s, and ringing may occur in the ears.
Other causes of high frequency hearing loss are attributed to family history. Age-related hearing loss is commonly passed down from generation to generation. It is important to inform your doctor if your family has a history of hearing loss.
Repeated exposure to loud noises like music concerts and listening to loud music though headphones are not only common causes, but preventable ones.
Another lesser known cause is smoking. People who smoke are more likely to suffer from this type of hearing loss than nonsmokers. Other medical conditions and medications have been linked to the loss of hearing at high frequencies.
As of yet, there is no cure for high frequency hearing loss. Treatment is focused on improving hearing rather than restoring it. Before treatments are issued, a full physical examination is given. The purpose of the full physical examination is to rule out any underlying medical conditions that may be causing the hearing loss.
The examination of the ear is not invasive nor is it painful. A doctor uses an instrument called an otoscope to examine the ears. In the best case scenario, your hearing loss will be attributed to wax blocking out noise.
In other cases, you may be referred to an ear, nose, and throat specialist for more in-depth testing at which time additional hearing tests will be performed.
The most common high frequency hearing loss treatment is the hearing aid. Hearing aids come in many varieties, sizes, and functionalities.
Your doctor will prescribe which hearing aid is best for you and explain to you how to properly use it. In some cases other assistive devices are used to aid in hearing such as telephone amplifiers.
For severe hearing loss, sign language, speech reading and visual cues to aid in communication are used.
Low Frequency Hearing Loss: Causes, symptoms, and how to deal with it.
When a person cannot hear low frequency sound waves, it is called low frequency hearing loss. The immediate cause of this is that the ear is impaired in its function, rendering it useless in picking up the low frequency vibrations from the surrounding environment. This short article will tell you more about the nature of this condition, what causes it, and how to deal with it.
First of all, low frequency hearing loss is the hardest kind to detect. This is because of many factors – the main among them being the fact that most of the low frequency sounds do not play that big a role in an average person’s life. Also, studies have suggested that most of the information that is contained in low frequency sound waves is also accompanied by waves in the mid- and high-frequency bands. Thus, the problem arises only if there is a source that emits only low frequency sounds – then the sufferer will not be able hear a single thing.
It has been found that this form of hearing loss is manifested with the improper hair growth or damage in the inner ear. Now there are several reasons for this to happen. One is that it is a genetic condition – and hence low frequency hearing loss is found to be a strongly inherited characteristic. Another cause might be a rare disease called Meniere’s disease, in which the membrane of the ear weakens and progressively deteriorates over time. Childhood illness or explicit ear infections may also lead to this condition.
Whatever be the cause, the treatments for this condition are limited. One method lies in the use of specifically designed hearing aids that catch the low frequency sounds and transmit them to the auditory cortex. However, most of the hearing aids in the market are designed to enhance high frequency sounds. Low frequency hearing aids are also available, though they might be slightly harder to get and more expensive than the high frequency, more common, ones.
Another difficulty is that it is more cumbersome to amplify low frequency sounds without amplifying the ambient noise. This, and a host of other problems, makes it hard to manage this particular condition. Yet, it is very important to detect low frequency hearing loss as early as possible, keep it under check, and it possible try to rectify/repair it. This is because thunder, traffic noises, barking dogs, etc. all comes under low frequency sounds.
Central Hearing Loss
There are many types of hearing loss. There might be damage to the outer ear, to the inner ear, or to the ear drum, and so on. A relatively more confusing hearing loss type is the central hearing loss.
In this case, the ears work just fine but some function in the central nervous system (mainly the brain) is lost so that the person cannot process what is being heard. Thus, the person finds it hard to understand or interpret what is being said.
This peculiar nature of this condition also results in the fact that people tend to diagnose it as a learning disorder. The sufferer is thought to have trouble understanding people and ideas and concepts and is attributed to a condition referred to as the central auditory processing disorder.
However, this is a wrong diagnosis because the person’s hearing is working just fine, only s/he cannot make any sense of what is being heard because of some loss of function in the auditory cortex.
Although studies on central hearing loss are increasing with each passing day, the amount of material available on it is still scratchy, and its fundamental nature is still elusive.
There are conjectures that it might be caused due to the erosion of the myelin sheath (which is the protective coating) of the nerve cells of the central nervous system. Another idea is that generally some kind of tumor in the auditory cortex might lead to central hearing loss.
The symptoms of this condition are that the sufferers have a hard time understanding what is being said – especially when the surrounding noise is a bit too much. There might be difficulty in reading, studying or focusing on the task at hand if there is a radio or a TV blaring in the room.
The sufferers might typically ignore the first few lines of what is being spoken to them in a conversation, more so if the suffer had been in a task which required them to be listening attentively.
Unfortunately, there is no direct cure to this condition. If it is being caused by a tumor – then steps can be taken to remove the tumor without harming the person and hope for recovery of function. Otherwise, all that can be done in the case of central hearing loss is to take alleviating measures.
For instance, it has been found that someone with central hearing loss perform better at tasks if they are made to carry out the task in a quiet environment.
Sudden Sensorineural Hearing Loss Needs Urgent Referral, Pauline Anderson [ Ref: http://www.medscape.com ]
Sudden Deafness, Part 1: Diagnosis and Treatment, Maurice H. Miller, Geriatrics and Aging. 2005;8(6):46-49
Idiopathic Sudden Sensorineural Hearing Loss, Steven D. Rauch, M.D. N Engl J Med 2008; 359:833-840August 21, 2008
Ceylan A, Celenk F, Kemaloglu YK, Bayazit YA, Göksu N, Ozbilen S: Impact of prognostic factors on recovery from sudden hearing loss. J Laryngol Otol 2007 , 121(11):1035-1040
National Institute on Deafness and Other Communication Disorders
[ Ref: http://www.nidcd.nih.gov ]
Harvard Medical School Center for Hereditary Deafness
[ Ref: http://hearing.harvard.edu ]
American Academy of Otolaryngology Head and Neck Surgery
[ Ref: http://www.entnet.org ]
American Speech-Language-Hearing Association. Type, Degree and Configuration of Hearing Losses.
[ Ref: http://www.asha.org/public/hearing/disorders/types.htm ]