What Is Hearing Loss?

Hearing loss is a condition that affects over 400,000 people across all age groups in NZ.

You might be surprised to know that:

65% of these people are below the age of 65. In the USA there are 6 million people between the age of 18 and 44 who suffer from hearing loss.

Common Types Of Hearing Loss

Sensorineural is the most common type of hearing loss with more than 95% of people with hearing loss being affected.

Sensorineural hearing loss occurs when there is damage to the inner ear (cochlea) or to the nerve pathways from the inner ear (retrocochlear) to the brain. Sensorineural hearing loss cannot be medically or surgically corrected. It is a permanent loss. It involves a reduction in the ability to hear faint sounds, but also affects speech understanding and ability to hear clearly.

Sensorineural hearing loss can be caused by diseases, birth injury, drugs that are toxic to the auditory system, and genetic syndromes. Sensorineural hearing loss may also occur as a result of noise exposure, viruses, head trauma, aging, and tumors.

Other Types Of Hearing Loss

CONDUCTIVE:

Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones, or ossicles, of the middle ear. It usually involves a reduction in sound level or the ability to hear faint sounds. This type of hearing loss can often be medically or surgically corrected.

Examples of conditions that may cause a conductive hearing loss include: Conditions associated with middle ear pathology such as fluid in the middle ear from colds, allergies (serous otitis media), poor eustachian tube function, ear infection (otitis media), perforated eardrum, benign tumors ,impacted earwax (cerumen), infection in the ear canal (external otitis), presence of a foreign body, or absence or malformation of the outer ear, ear canal, or middle ear.

MIXED:

Sometimes a conductive hearing loss occurs in combination with a sensorineural hearing loss. In other words, there may be damage in the outer or middle ear and in the inner ear (cochlea) or auditory nerve. When this occurs, the hearing loss is referred to as a mixed hearing loss.

DEGREE OF HEARING LOSS:

There are 5 Broad Categories Typically Used:

Normal range or no impairment = 0 dB to 20 dB

Mild loss = 20 dB to 40 dB

Moderate loss = 40 dB to 60 dB

Severe loss = 60 dB to 80 dB

Profound loss = 80 dB or more

CONFIGURATION OF THE HEARING LOSS

The configuration or shape of the hearing loss refers to the extent of hearing loss at each frequency and the overall picture of hearing that is created. For example, a hearing loss that only affects the high frequencies would be described as a high-frequency loss. Its configuration would show good hearing in the low frequencies and poor hearing in the high frequencies. On the other hand, if only the low frequencies are affected, the configuration would show poorer hearing for low tones and better hearing for high tones. Some hearing loss configurations are flat, indicating the same amount of hearing loss for low and high tones.

Other descriptors associated with hearing loss are:

Bilateral versus unilateral. Bilateral hearing loss means both ears are affected. Unilateral hearing loss means only one ear is affected.

Symmetrical versus asymmetrical. Symmetrical hearing loss means that the degree and configuration of hearing loss are the same in each ear. An asymmetrical hearing loss is one in which the degree and/or configuration of the loss is different for each ear.

Progressive versus sudden hearing loss. Progressive hearing loss is a hearing loss that becomes increasingly worse over time. A sudden hearing loss is one that has an acute or rapid onset and therefore occurs quickly, requiring immediate medical attention to determine its cause and treatment.

Fluctuating versus stable hearing loss. Some hearing losses change – sometimes getting better, sometimes getting worse. Fluctuating hearing loss is typically a symptom of conductive hearing loss caused by ear infection and middle ear fluid, but also presents in other conditions such as Meniere's disease.

Untreated Hearing Loss.

Untreated hearing loss has many detrimental effects on the patient. There have been many studies done that demonstrate the effects of untreated hearing loss. Hearing impaired individuals who do not wear hearing aids are significantly more likely to suffer from depression, anxiety, paranoia and emotional turmoil compared to similar aged persons who wear hearing aids. When elderly hearing impaired individuals are fitted with hearing aids there is consistent improvement across all areas of life. The family members often noticed even more improvement from the use of the hearing aids than the patients. They noticed improvement in every aspect of life, from interaction with grandchildren to the family member being more independent with the hearing aids.

The chart below reflects the paragraph above. There was a statistically significant difference across all areas examined.

Patient Family

  Before After
Relations at home 56% 66%
Feelings about self 50 60
Life overall 48 62
Mental health 36 39
Self-confidence 39 46
Relations with children, grandchildren 40 52
Sense of safety 34 37
Social life 34 41
Relations at work 26 43
Sex life    


National Council On Aging (NCOA) study from May 1999.

Two Hearing Aids.

If you have hearing loss in both ears you need to wear two hearing aids in order to fully benefit from amplification. Hearing from both ears allows you to tell the direction sound is coming from. Without this ability you cannot focus on the person in front of you when you are in a noisy situation. It makes it extremely difficult to understand in noise and even in quiet environments it is more challenging. The two ears communicate with each other and stimulate different parts of the brain to determine the message.