SHAH ALAM - While a child's babbling and laughter are a joy for parents, hearing loss can mute this soundscape for some families.
Though prevalent, it can be effectively addressed with early detection and intervention.
Here's what Malaysian parents should know:
Signs and symptoms:
Infants and Toddlers
Key signs of hearing loss in infants and toddlers include a lack of response to sounds or the mother’s voice.
Parents should observe if there is an absence of a startle reflex to loud noises and delays in speech and language development.
Difficulty locating the source of sounds, often linked to frequent ear infections, is another important indicator.
According to US' largest hearing clinic directory Healthy Hearing, speech and hearing milestones can help gauge a child's hearing development.
From birth to four months, babies should startle at loud sounds, wake up or stir at loud noises, respond to their parent's voice by smiling or cooing, and calm down at a familiar voice.
Between four to nine months, infants should smile when spoken to, notice sound-making toys, turn their heads toward familiar sounds, make babbling noises, and understand hand motions like the bye-bye wave.
From nine to fifteen months, they should make various babbling sounds, repeat simple sounds, understand basic requests, use their voice to get attention, and respond to their name.
From fifteen to twenty-four months, toddlers should use many simple words, point to body parts when asked, name common objects, listen to songs, rhymes, and stories with interest, point to familiar objects when named, and follow basic commands.
Preschool and School-Age Children
In older children, hearing loss may manifest as inattentiveness, difficulty following instructions, frequent requests for repetition, and turning up the volume on electronic devices.
Poor academic performance, especially in reading and language subjects, social withdrawal, and behavioral issues are also common signs.
Healthy Hearing noted that older children might develop hearing loss that was not previously evident.
Signs include difficulty understanding speech, speaking differently from peers, not responding when called by name, inappropriate responses due to misunderstandings, turning up the TV volume excessively or sitting very close to the TV, and academic problems.
Difficulty understanding phone conversations and frequent switching ears while talking on the phone can also indicate hearing issues.
Many children with hearing loss become adept at lip-reading, which can delay detecting their hearing problems.
Other indicators include speech or language delays, problems articulating words, imitation of others' actions, and complaints of ear pain or noises.
Causes of Hearing Loss:
Hearing loss in children can be categorised as congenital (present at birth) or acquired (developed after birth).
Congenital Causes
Congenital hearing loss is often due to genetic factors.
A family history of hearing loss, infections during pregnancy (such as rubella, syphilis, or cytomegalovirus), premature birth, low birth weight, and birth complications (like lack of oxygen or jaundice requiring blood transfusion) can all contribute to congenital hearing loss.
Healthy Hearing highlighted that genetic factors cause more than 50 per cent of hearing loss in children.
Autosomal recessive hearing loss accounts for about 56 per cent of genetic cases.
In this scenario, neither parent has hearing loss but carries a recessive gene passed to the child.
Autosomal dominant hearing loss accounts for around 15 per cent of genetic cases, where one parent with a dominant gene passes it to the child, sometimes without exhibiting hearing loss but showing other genetic syndrome signs.
Congenital hearing loss can also result from genetic syndromes (such as Usher or Down syndrome) and non-genetic factors like birth complications, infections, premature birth, low birth weight, and maternal use of ototoxic drugs.
Other maternal risk factors include infections during pregnancy, diabetes, drug or alcohol abuse, and smoking.
Non-genetic factors account for about 25 per cent of congenital hearing loss, with the remaining 25 per cent often having no identifiable cause.
Acquired Causes
Acquired hearing loss occurs after birth and can result from infections (meningitis, measles, mumps, whooping cough), head injuries, exposure to loud noises, ototoxic medications, and untreated or frequent ear infections (otitis media).
Other causes include a perforated eardrum, otosclerosis, Meniere's disease, and exposure to second-hand smoke or other toxins.
Temporary hearing loss is also a concern, with transient or fluctuating hearing loss potentially affecting speech and language development.
Otitis media, or middle ear infections, are a common cause of transient hearing loss in children.
The Eustachian tube’s position during childhood makes it prone to blockage by fluids or large adenoids, leading to infections.
While this type of hearing loss usually resolves itself, frequent untreated infections can cause cumulative damage, leading to permanent sensorineural hearing loss.
Hearing loss is prevalent among Malaysian children, with varying statistics across age groups.
The National Burden of Disease and Injury Study 2001 revealed that deafness is the second most common non-fatal condition in Malaysia, following unipolar depression, diabetes, and osteoarthritis.
A 2006 survey by the Institute of Public Health found that 21.57 per cent of Malaysians experience hearing loss, defined as the loss of hearing in any tested frequency.
The prevalence increases with age. The Health Ministry’s MyHealth Portal reported that 63 per cent of individuals above 56 years experience hearing loss. Among the working population aged 18 to 55 years, 16.1 per cent are affected.
For secondary school children aged 13 to 17 years, the prevalence is 3.5 per cent.
For primary school children aged 7 to 12 years, and pre-school children aged 3 to 6 years, the rates are 6.6 per cent each.
Meanwhile, 3.83 per cent of the population suffers from moderate to severe deafness, requiring assistive devices such as hearing aids.