Types of Hearing Loss

The external ear and the middle ear conduct sound, and the inner ear receives the sound. A problem in the external or middle ear may result in a conductive hearing impairment. A problem in the inner ear may result in a sensorineural hearing impairment. Both types of problems may exist at the same time, resulting in a mixed hearing impairment.

A conductive hearing impairment may result from blockage of the external ear canal, from a hole in the eardrum, from middle ear infection or from disease of any of the three middle ear bones. A conductive hearing impairment can often be corrected medically. If not, a hearing aid is often useful.

A sensorineural hearing impairment may result from damage to the nerve endings in the inner ear. The damage can occur because of a lack of blood circulation, or change in the fluid pressure in the inner ear. Physical damage to the nerve endings from intense noise or drugs is also common. The most common cause of sensorineural hearing impairment is a change in the nerve endings as the result of aging. This type of impairment is not correctable with surgery or medicine, but can often be helped with hearing aids.

According to the Better Hearing Institute in February 2010, the number of Americans with hearing loss has grown to more than 34 million, or roughly 11 percent of the U.S. population. The study found that over the last generation, hearing loss among Americans has increased at a rate of 160 percent of U.S. population growth and is one of the most commonly unaddressed health conditions in America today. The prevalence of hearing loss over the last 20 years has grown from 266 to 295 people per thousand U.S. households.

Sergei Kochkin, PhD, executive director of BHI, has stated, “Unaddressed hearing loss silently creeps into virtually every aspect of daily living and seriously erodes quality of life.”  “The issue of moving a person from admission of their hearing loss, to recognition of the problems hearing loss causes in their lives, to positive action to treat their hearing loss, is extremely complex and multi-dimensional. Early education to achieve recognition of hearing loss and information on the value of hearing healthcare must remain priorities for the foreseeable future.”

The effects of untreated hearing loss can be especially devastating for children. Even a mild hearing loss can have a negative impact on language competence, cognitive development, social and emotional well-being, and academic achievement.

If have a hearing loss much greater in one ear, or if you are suffering from dizziness, your physician may order a Cat Scan to rule out a serious problem.   Permanent sensorineural hearing loss could result from constant exposure to intense noise. Thousands of workers are exposed the noise each day.  These individuals should wear hearing protection.

Also, playing and listening to loud music can cause a sensorineural hearing loss.  Musicians who play their music several hours each week are often at risk for hearing loss.  It is important to remember that it is not only rock musicians who are at risk.  Symphony orchestra musicians  are also at risk.  Special ear plugs are available for musicians to protect their hearing while performing. Musician's ear plugs use special filters developed at Etymotic Research.  The special ear plugs are designed to bring the level of the music down to a safe level while maintaining good music quality for the musician.  The ear plugs are custom fit.  Ear impressions are taken of the musician's ears, and the Etymotic filters are fitted into the ear mold.  There are different filters with different attenuation values.  An audiologist will help determine which filter the musician should use.

Recruitment is a term to describe an abnormal growth in loudness.  Recruitment is often present for people with nerve loss.  Because of the patient’s hearing loss, they often cannot hear normal conversation or other environmental sounds.  However, loud sounds can often cause much discomfort.  People with normal hearing may not experience the same discomfort to the same intense sound.  The abnormal growth in loudness can be extremely irritating and should be taken into account when selecting hearing aids.Patients with recruitment usually cannot tolerate hearing aids with linear circuits.  Linear circuits make no attempt to protect individuals from loud sounds such as a loud jet flying by or other intense noises.  Linear circuits provide the same amount of gain for all sounds.  The end result is that intense sounds are too loud and people will not wear the aids.  Compression technology is available to help keep loud sounds comfortable.  Compression circuits apply less volume for loud sounds automatically, and provide the listener with a much more pleasant listening experience.

Tinnitus is the term used to describe ringing, roaring and other ear noises.  Approximately forty million people in this country suffer from tinnitus.  More than seven million people are affected so severely that they cannot lead normal lives.  Tinnitus usually results from damage to the microscopic hair cells in the inner ear.  Two of the causes of hair cell damage include aging, and noise exposure.  A dull sense of hearing and tinnitus often occur following noise exposure.  That is called a temporary threshold shift.  If someone exposes himself or herself to the same noise day after day, the temporary shift can become permanent.