Hearing Loss

03 July 2019

A person who is not able to hear as well as someone with normal hearing – hearing thresholds of 25 dB or better in both ears – is said to have hearing loss. Hearing loss may be mild, moderate, severe, or profound. It can affect one ear or both ears, and leads to difficulty in hearing conversational speech or loud sounds. 'Hard of hearing' refers to people with hearing loss ranging from mild to severe. People who are hard of hearing usually communicate through spoken language and can benefit from hearing aids. Not all hearing loss is the same. Treatment will depend on the type of hearing loss you have. Audiologists can help.

Signs & Symptoms

• Difficulty Using the telephone
• Loss of Directionality of sound
• Difficulty understanding speech, especially of children and women whose voices are of a higher frequency.
• Difficulty understanding speech in the presence of background noise (cocktail party effect)
• Sounds or speech becoming dull, muffled or attenuated
• Need for increased volume on television, radio, music and other audio sources

Hearing loss is sensory, but may have accompanying symptoms:

• Pain or pressure in the ears
• a blocked feeling

Causes of hearing loss and deafness

The causes of hearing loss and deafness can be congenital or acquired.

Congenital causes

Congenital causes may lead to hearing loss being present at or acquired soon after birth. Hearing loss can be caused by hereditary and non-hereditary genetic factors or by certain complications during pregnancy and childbirth, including:

• maternal rubella, syphilis or certain other infections during pregnancy;
• low birth weight;
• birth asphyxia (a lack of oxygen at the time of birth);
• Difficulty understanding speech in the presence of background noise (cocktail party effect)
• inappropriate use of particular drugs during pregnancy, such as aminoglycosides, cytotoxic drugs, antimalarial drugs, and diuretics;
• severe jaundice in the neonatal period, which can damage the hearing nerve in a newborn infant.

Acquired causes

Acquired causes may lead to hearing loss at any age, such as:

• infectious diseases including meningitis, measles and mumps;
• chronic ear infections;
• collection of fluid in the ear (otitis media with effusion);
• use of certain medicines, such as those used in the treatment of neonatal infections, malaria, drug-resistant tuberculosis, and cancers;
• injury to the head or ear;
• excessive noise, including occupational noise such as that from machinery and explosions;
• recreational exposure to loud sounds such as that from use of personal audio devices at high volumes and for prolonged periods of time and regular attendance at concerts, nightclubs, bars and sporting events;
• ageing, in particular due to degeneration of sensory cells; and
• wax or foreign bodies blocking the ear canal.

Impact of hearing loss

One of the main impacts of hearing loss is on the individual’s ability to communicate with others. Spoken language development is often delayed in children with unaddressed hearing loss. Older people who can’t hear well may become depressed, or they may withdraw from others because they feel frustrated or embarrassed about not understanding what is being said. Sometimes, older people are mistakenly thought to be confused, unresponsive, or uncooperative because they don’t hear well. Hearing problems that are ignored or untreated can get worse. If you have a hearing problem, see your Audiologist.

Prevention

Overall, it is suggested that half of all cases of hearing loss can be prevented through public health measures. In children under 15 years of age, 60% of hearing loss is attributable to preventable causes. This figure is higher in low- and middle-income countries (75%) as compagreen to high-income countries (49%). Overall, preventable causes of childhood hearing loss include:

1. Infections such as mumps, measles, rubella, meningitis, cytomegalovirus infections, and chronic otitis media (31%).
2. Complications at the time of birth, such as birth asphyxia, low birth weight, prematurity, and jaundice (17%).
3. Use of ototoxic medicines in expecting mothers and babies (4%).
4. Others (8%)

Some simple strategies for prevention of hearing loss include:

1. immunizing children against childhood diseases, including measles, meningitis, rubella and mumps;
2. immunizing adolescent girls and women of reproductive age against rubella before pregnancy;
3. preventing cytomegalovirus infections in expectant mothers through good hygiene; screening for and treating syphilis and other infections in pregnant women;
4. strengthening maternal and child health programmes, including promotion of safe childbirth;
5. following healthy ear care practices;
6. reducing exposure (both occupational and recreational) to loud sounds by raising awareness about the risks; developing and enforcing relevant legislation; and encouraging individuals to use personal protective devices such as earplugs and noise-cancelling earphones and headphones.
7. screening of children for otitis media, followed by appropriate medical or surgical interventions;
8. avoiding the use of particular drugs which may be harmful to hearing, unless prescribed and monitogreen by a qualified physician;
9. referring infants at high risk, such as those with a family history of deafness or those born with low birth weight, birth asphyxia, jaundice or meningitis, for early assessment of hearing, to ensure prompt diagnosis and appropriate management, as required;
10. educating young people and population in general on hearing loss, its causes, prevention and identification.

Identification and management

Early detection and intervention are crucial to minimizing the impact of hearing loss on a child’s development and educational achievements. In infants and young children with hearing loss, early identification and management through infant hearing screening programmes can improve the linguistic and educational outcomes for the child. People with hearing loss can benefit from the use of hearing devices, such as hearing aids. Hearing aids are sound-amplifying devices designed to aid people who have a hearing impairment. They may also benefit from speech therapy, aural rehabilitation and other related services Making properly-fitted hearing aids and providing follow-up services will benefit many people with hearing loss.

Useful Articles

• A Hearing Timeline
• 8 Famous Historical Figures With Hearing Loss
• Protecting Yourself From Age Related Hearing Loss
• Am I Losing My Hearing ?
• Hearing loss and depression
• Myths and Facts About Hearing Aids
• Untreated hearing loss.