Hearing Loss in Adults

Overview/Pathophysiology

The human ear functions to provide sound, speech, and balance information to the brain. There are three main components of the human ear. The external ear includes the pinna (or outer ear), ear canal, and eardrum. The middle ear includes the three hearing bones, or ossicles. From the eardrum to the inner ear, the three ossicles are the hammer, anvil, and stirrup – the malleus, incus, and stapees. The inner ear includes the cochlea, the organs of balance, the hearing nerve (auditory nerve), and the balance nerves (vestibular nerve).

Hearing loss is a common medical condition. but is often underdiagnosed. There are two major types of hearing loss – conductive hearing loss and sensorineural hearing loss. Both categories of hearing loss can occur gradually or suddenly. A sudden hearing loss, especially in one ear, can be a medical emergency.

Conductive hearing loss occurs when sound cannot reach the inner ear due to a problem of the outer or middle ear. Common problems that can cause conductive hearing loss include ear wax (cerumen), outer ear infection (otitis externa or swimmers ear), a hole in the eardrum, (tympanic membrane perforation), negative pressure of the middle ear (Eustachian tube dysfunction), or fluid in the middle ear. (otitis media).

Other causes of conductive hearing loss can include a tumor, or cyst in the middle ear, (cholesteatoma), damage of the hearing bones, (ossicles) due to negative pressure changes/infection/previous ear surgery, or stiffening of the joints of the ossicles. (such as otosclerosis).


Less common causes of conductive hearing loss can include abnormalities of the inner ear, such as superior semicircular canal dehiscence (SSCD) or large vestibular aqueduct syndrome (LVAS).

Sensorineural hearing loss occurs following a problem of the inner ear. It is the most common neurologic disability in the U.S. Aging is associated with hearing loss, and this is common condition called presbycusis. One third of patients over 60 years old and one half of patients over 85 have this type of hearing loss. Noise exposure, either at work or recreationally, is another important can also cause of sensorineural hearing loss. A patient will often note a history of hearing loss in the family, suggesting that there may be genetic factors in certain individuals with sensorineural hearing loss. In some cases, autoimmune factors can cause fluctuating hearing loss in both ears. Other conditions of the inner ear that cause dizziness, like A condition called Menieres disease cab sometimes cause sensorineural hearing loss. A severe head injury or skull fracture can cause conductive or sensorineural hearing loss. In rare cases, a benign tumor called a vestibular schwannoma (acoustic neuroma) can cause gradual or sudden sensorineural hearing loss in one ear.

Finally, there are some patients that have both a conductive and sensorineural hearing loss in the same ear.

Key points:

• There are two types of hearing loss: conductive and sensorineural; both can occur gradually or suddenly
• Conductive hearing loss is due to a problem with the outer or middle ear, such as ear wax, middle ear infections, or a ruptured ear drum
• Sensorineural hearing loss is caused by problems with the inner ear

What are the Symptoms?

The symptoms of hearing loss can be gradual or sudden. A sudden hearing loss IS A MEDICAL EMERGENCY until proven otherwise by a complete audiologic and medical evaluation. A sudden hearing loss can be associated with an upper respiratory infection or flu-like symptoms.

Adult patients with hearing loss can experience a “blocked” or “fullness” sensation in the involved ear. Sounds and words can sound muffled or in severe cases, completely absent. Patients will often complain that Sounds may be muffled, and understanding speech may be difficult, especially with background noise (i.e., in a restaurant, party or a crowded office).

A spouse may comment that the TV has be turned up higher than usual, or that the patient does not always respond to his or her voice. Usually, high-pitched voices (children, women) become more difficult to understand as many patients lose their high frequency hearing first.

Tinnitus (ringing) of the ears is a very common complaint in patients with sensorineural hearing loss. and is often associated with sensorineural hearing loss. Tinnitus can be high pitched or low pitched, it can change in intensity from day to day. and be quite unpredictable in its course. Tinnitus is felt to be due to the uncontrolled activity of nerves of the inner ear and the brain, and there is NO medical intervention that cures tinnitus. Over time, most patients become accustomed to the sensation, and In some cases, this can improve with hearing aids. IF they are candidates for amplification.


Key points:

• Symptoms of hearing loss can be gradual or sudden.
• Tinnitus is commonly experienced with sensorineural hearing loss.
• Muffled sounds and difficulty understanding words in background noise may occur.

What are the risk factors?

The Risk factors for hearing loss depend on the type of hearing loss (conductive or sensorineural) and the cause. of the hearing loss.

Conductive hearing loss

Wax, or cerumen impaction causing conductive hearing loss can be worsened with Inappropriate use of Q-tip use or attempts to clean the ear canal with bobby pins can cause ear wax to block the ear canal and increase the risk of hearing loss. , etc.

Swimming increases the risk of infection and hearing loss. otitis externa or swimmer’s ear can be caused or worsened by excessive Q-tip use, freshwater exposure, or poorly controlled diabetes.

Allergies, a cold or flu, sinusitis, or a history of middle ear infections as a child can also increase the risk can predispose an adult to develop an otitis media.

A recent descent in an airplane causing pain and fullness of the ears can be associated with conductive hearing loss from the persistent negative pressure of the middle ear.

Sensorineural hearing loss

Noise exposure from loud machines, music, gun shots, or power tools is a common cause of hearing loss. Noise exposure can come from occupational hazards such as loud machines and military service, and recreational exposure such as loud music, hunting or shooting, or the use of power tools.

For example a personal stereo or MP3 player can be as loud as 105-110 decibels. A rock concert can be 110-120 decibels, and a firecracker is 150 decibels or more.

Power tools in a woodshop or a snowmobile can be as loud as 100-105 decibels.

Regular exposure of longer than ONE MINUTE at 110 decibels risks permanent hearing loss.

At 100 decibels, longer than 15 minutes of unprotected exposure risks permanent hearing loss.

A family history of hearing loss is commonly seen in patients with sensorineural hearing loss.

Severe head trauma or skull fracture is a risk factor for sensorineural hearing loss.

Exposure to medications like certain intravenous antibiotics and chemotherapy for cancer may cause permanent sensorineural hearing loss.

Medical conditions like diabetes, autoimmune diseases, and heart disease are associated with a greater risk of hearing loss. Autoimmune conditions are also associated with hearing loss.

How is it diagnosed?

A complete medical evaluation by a board-certified otolaryngologist or otologist and a complete audiologic evaluation by an audiologist in a sound-proof chamber is essential for diagnosing hearing loss. determining the cause of hearing loss.

A careful Physical examination of the ears will quickly determine if can reveal if there is wax, fluid or pus build-up, or a ruptured ear drum causing the hearing loss. the external ear or eardrum is the cause of the eardrum. Occasionally, fluid or pus can be seen behind an intact eardrum, and an otitis media will be diagnosed. The hearing bones – ossicles – and inner ear can be difficult to assess on the physical examination.

Most importantly, A complete hearing test can help determine if the hearing loss is conductive or sensorineural. Testing will also determine if the eardrum is not moving well (scar, perforation, or fluid), whether the hearing bones – ossicles – are stiff or mobile), and if the inner ear and auditory nerve are able to work together to understand words.

In some cases, a high resolution temporal bone CT scan may be ordered to rule out a chronic middle ear and mastoid infection, a tumor such as a cholesteatoma, and other abnormalities of the temporal bone.

A MRI scan can also help rule out tumors. , WITH GADOLINIUM CONTRAST, is ordered if a patient has sensorineural hearing loss that involves one ear more than the other, to exclude the possibility of a benign tumor like a vestibular schwannoma (also known as acoustic neuroma).

Treatment

Treatment options will depend on the condition that causes the hearing loss.

A cerumen impaction should be carefully removed in the office using a surgical microscope.

Wax build up can be removed by a doctor

An otitis externa or swimmers ears Infections are treated with antibiotic ear drops or oral antibiotics ALONE in an otherwise healthy person.

More stubborn infections require a careful cleaning of the ear in a otolaryngologist’s office and possibly oral antibiotics.

Patients with poorly controlled diabetes MUST improve glucose control in otitis externa or they are at risk of developing a dangerous infection called malignant otitis externa.

Otitis media is treated with antibiotics, and the fluid in the middle ear that persists and causes conductive hearing loss can be managed with oral and nasal decongestant until the fluid disappears.

In cases where fluid from otitis media in the middle ear does not resolve, a simple, relatively painless and safe 3 minute procedure in the office can be performed.

This procedure is performed by an otolaryngologist who makes a small opening in the eardrum – called a myringotomy can be performed. Tubes are sometimes placed in the ear to assist with drainage of fluid.

A tympanostomy tube can also be placed at the same time to provide adequate ventilation and to allow for evacuation of fluid that does NOT drain through the Eustachian tube.

Other types of conductive hearing loss such as cyst or middle ear tumor (cholesteatoma), or stiffening or damage to the hearing bones – ossicles – may require a surgical procedure.

Patients who present with SENSORINEURAL hearing loss have fewer options. If the sensorineural hearing loss is slowly progressive, over months and years, there are no treatment options, yet. This is permanent hearing loss and hearing aids may be beneficial if there is enough word understanding.

For patients who have little to no word understanding, and severe to profound hearing loss (deafness) in BOTH ears, a cochlear implant may be performed. a reasonable option.

A cochlear implant is a bionic device, This involves implantation of a miniature computer and electrode that aids in hearing., that is placed surgically into the deaf inner ear when conventional hearing aids no longer benefit the patient.

A patient with a sudden, or fluctuating sensorineural hearing loss may be a candidate for steroids, given by mouth or injected into the middle ear.

For those patients with one deaf ear and one normal ear, a bone-anchored hearing aid or a CROS hearing aid may be helpful to bring sound from the bad ear to the better hearing ear. Hearing aids are an option for people with permanent sensorineural hearing loss.

Key Points:

• Treatment for hearing loss depends on the type and cause
• Removal of wax, antibiotics to treat infection, and a procedure called myringotomy can help with hearing loss that is due to problems with the external or middle ear
• Sensorineural hearing loss is often permanent. Hearing aids and in extreme cases cochlear implants can help improve hearing

Are there any complications?

A sudden sensorineural hearing loss in one ear, if not treated with STEROIDS within ONE to TWO weeks of when it first began, could become a PERMANENT hearing loss. WHY? WHAT IS THE CAUSE? WITHOUT THIS INFORMATION THIS IS CONFUSING AT BEST. Often, the ear will “look” normal to a primary care physician and usually there is no pain. If you suspect that you have this condition, please seek care by an otolaryngologist ASAP.

Sensorineural hearing loss in one ear caused by a vestibular schwannoma can worsen if the tumor grows, and decrease the chances that hearing can be saved during surgical removal, if indicated. THIS IS ONE OF SEVERAL COMPLICATIONS INVOLVED WITH HEAIRNG LOSS… WHAT ABOUT HEAD INJURIES, BRAIN TUMORS, ETC. AGAIN, I WOULD DELETE THIS SECTION.

In the past, hearing loss was often regarded as an “invisible disability.” Unfortunately, Chronic hearing loss that goes undiagnosed or untreated can result in impaired communication, isolation, depression, and anxiety. Many elderly patients with hearing loss couldbenefit from When appropriate, hearing aids can help improve hearing and its consequences. that are smaller and more powerful than older devices.

Hearing loss associated with chronic infections, Eustachian tube dysfunction, or cholesteatoma can worsen if not managed with medication or surgery.
Sensorineural hearing loss in one ear caused by a vestibular schwannoma can worsen if the tumor grows, and decrease the chances that hearing can be saved during surgical removal, if indicated.

A sudden sensorineural hearing loss in one ear, if not treated with STEROIDS within ONE to TWO weeks of when it first began, could become a PERMANENT hearing loss.
Often, the ear will “look” normal to a primary care physician and usually there is no pain. If you suspect that you have this condition, please seek care by an otolaryngologist ASAP.

Fast Facts

• Hearing loss is a common problem that can come on suddenly or gradually. Sudden hearing loss may be caused by a serious medical problem and should be treated immediately
• There are two types of hearing loss: Conductive and sensorineural
• Conductive hearing loss is caused by a problem of the outer or middle ear, such as ear wax build up, infections, or ruptured ear drums, that prevents sound from passing into the inner ear
• Sensorineural hearing loss is caused by problems in the inner ear or nerves that conduct sound
• People with hearing loss should be seen by an ear specialist (otolaryngologist or otologist) and have their hearing tested by an audiologist
• Treatment for hearing loss depends on the type and cause:
• With conductive hearing loss, the problem causing the symptoms should be treated – e.g., ear wax should be removed, infections should be treated
• Sensorineural hearing loss is often permanent; measures to improve hearing (hearing aids, cochlear implants) may be recommended
• For more information on hearing loss, visit: http://www.cdc.gov/ncbddd/dd/ddhi.htm

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