HEARING LOSS

Test Your Hearing | How We Hear | Hearing Loss | Communicating with the Hard of Hearing

It is not surprising that things can go wrong in the elaborate auditory system, and these problems can result in a reduced ability to hear.

Hearing losses are grouped into four categories - central / retro-cochlear, conductive, sensorineural and mixed.

Central or Retro-cochlear Loss

This least common form of hearing impairment occurs when there is a problem in the central auditory system. Although the outer, middle and inner parts of the ear deliver sound signals, these signals are unable to be processed by the brain. Amplification does not help this type of dysfunction.

Conductive Loss

More frequent than central hearing loss, conductive hearing impairment results from malfunction of the outer and/or middle ear. Conductive losses can be caused by something as simple as impacted earwax, or something as serious as middle ear infection, eardrum perforation or disarticulation of the ossicles.

Many of these problems can be medically or surgically treated and hearing health care professionals are obligated to report such conditions to clients' physicians. When treated in time, some conductive losses may not require amplification. Other conductive losses are untreatable and in these cases hearing instruments are an important consideration.

Sensorineural Hearing Loss

Sensorineural hearing loss is by far the most common type of impairment. It is usually the result of cochlear haircell damage; the outer and middle ear conduct sound to the inner ear, but some haircells are unable to "trigger" and therefore cannot send signals to the central auditory system.

Because the cochlea is tiny and the haircells themselves are microscopic, no medical procedure can "fix" sensorineural hearing loss. The cochlea lies deep within the skull's temporal bone and cannot be reached without ruining all the haircells. Unlike conductive hearing losses, sensorineural hearing loss is considered permanent and irreversible.

Fortunately, sensorineural loss can be aided with amplification, which makes sounds louder so that remaining healthy haircells can respond and trigger nerve impulses.

Although hearing instruments help people with hearing loss, there is nothing that can restore sensorineural impairment and no hearing instrument can compensate for damaged hearing at every pitch. Nonetheless, hard of hearing people are able to enjoy improved communication as a result of using hearing instruments.

Several things can cause sensorineural hearing loss, such as:

• hereditary predisposition

• prenatal, perinatal or congenital factors (i.e.: thalidomide)

• disease

• prolonged exposure to excessive noise

• ototoxic medication

• chemotherapy

• age

Age is the most prevalent cause of hearing impairment. Presbycusis is the term given to age-induced hearing loss which occurs as part of the natural deterioration of the human body as it grows older.

Mixed Loss

Mixed hearing loss is a condition in which both conductive and sensorineural hearing loss is present.

Myths About Hearing Loss

Myth 1

If you say something loudly enough, it will be heard.
This widely held view about hearing loss is not entirely true. Many people with sensorineural hearing loss also suffer from a condition called recruitment, which is a heightened sensitivity to loud sounds. Although soft sounds need to be amplified before they are heard, loud sounds are uncomfortable and physically intolerable at intensities which do not bother people with normal hearing. For this reason, raising your voice may cause distortion of speech and even physical discomfort for some hard of hearing listeners.

Myth 2

Sensorineural hearing loss occurs in the same amounts across all frequencies. Some hearing losses are evenly spread across the frequency spectrum. These are called flat losses. Most sensorineural hearing losses are more impaired in high and ultra-high frequencies than the low frequencies. These are called sloping losses. Another, less common type hearing loss is a reverse loss in which high frequencies are heard better than low frequencies.

These hearing losses derive their names from the shape made when the hearing thresholds are graphed. Loudness in decibels (dB) is measured on the vertical axis and frequency in Hertz (Hz) is measured on the horizontal axis. Graphs of this sort are called audiograms and provide an initial, visual depiction of the severity and frequency specifics of a hearing condition.

Myth 3

Hearing aids didn't work for someone I know, so they won't work for me. Adjustment to amplification is a process which can take many months. People who don't expect a restoration of they're natural hearing and who are willing to wear their instruments regularly in order to become used to the new sounds will enjoy the benefits of improved communication. People who try their hearing aids once or twice and then give up do not receive any benefit. As with any endeavor, people get out of amplification what they are willing to put into it.

What does all this mean to your daily life? The effects of untreated hearing loss can be devastating. Many hard of hearing people are unaware of their hearing loss. Others may know that there is a problem, but have not accepted it. There are stigmas attached to hearing impairment that nobody wants to associate themselves with such as being elderly, being dependent, being incompetent. Think of the insinuations of the phrase "senile."

Ultimately, however, a reduction in the ability to hear means a reduction in the ability to communicate. Many hard of hearing individuals suffer from feelings of isolation - many withdraw from others even more as a result of their loss. Relationships are strained when one member has an undiagnosed hearing loss, or even worse, when nothing is done about a known hearing loss.

Most people wear hearing instruments to improve their understanding of speech. Speech is an extremely complex sound signal, composed of many intensities, tones, and tonal and harmonic peaks. These components must be heard in order to assimilate, assemble and translate signals into recognizable words.

Most vowels are low pitched with relatively high intensities. Several consonants are high or ultra-high in pitch and low in intensity. People with sloping, high-frequency hearing losses, which are the most common type of hearing loss, can hear vowel sounds, but miss many consonant sounds, particularly the f, s, th, v and c.

The resulting fragmented perception of speech usually sounds loud enough, but is unclear. This explains why the hard of hearing sometimes think that other people mumble.

In quiet, one-on-one conversation missing the odd word does not matter very much. We all speech-read to some degree and this often helps.

When listening conditions are not ideal, understanding is considerably reduced. Some common scenarios where listening is very difficult for the hearing impaired are:

• a dinner table where there is more than one conversation taking place

• a party where there is a lot of background noise

• when the person speaking does not face his or her audience

• in a vehicle where there is road noise

• in wind

There is a saying which states that the best way to make a hearing loss obvious is to do nothing about it. Here are some behaviours common to hard of hearing individuals:

• listening to TV or radio at very high volume levels

• frequent inappropriate conversational responses

• domination of discussions

• avoidance of discussions

• difficulty using telephones

• complaints that others mumble

• frequent requests for repetition of phrases

• denial of hearing loss and an unwillingness to have a hearing assessment

It is common for loved ones to notice a hearing loss before it recognized by hard of hearing individuals. Rarely does hearing loss occur suddenly. Individuals adapt during the gradual development of their hearing loss so that listening with impaired ears becomes "the norm." The almost imperceptible changes in hearing sensitivity usually go unnoticed, so some people who are hard of hearing consider their inability to understand speech to be the result of external factors such as "too much background noise" or other people "mumbling."

By performing tests, doctors and hearing health professionals are able to determine:

• the presence of hearing loss

• its "type" and whether medical intervention is necessary

• its severity

• at what frequencies hearing is most impaired, or the "shape" of the loss

• whether hearing instruments would be beneficial

If you suspect that you or a loved one may have impaired hearing, get it checked by a doctor or an A & B Hearing Aid and Audiology Center, hearing health care professional.

Test Your Hearing | How We Hear | Hearing Loss | Communicating with the Hard of Hearing

Copyright © 1999-2003 "A & B Hearing Aid and Audiology Center". All Rights Reserved.
"A & B Hearing Aid and Audiology Center"® is a fully insured company.
6609 Blanco Road, Suite 115, San Antonio, Texas 78216
Office: 210-342-2299 | Fax: 210-342-5499
Notice of Privacy Practices - H.I.P.P.A.