Hearing Loss In Babies: Everything Parents Need To Know

If your baby isn't responding to your calls, it's a good idea to consult a specialist. 

According to the Indian Academy of Pediatrics, “Hearing loss is the most common sensory birth deficit, occurring in 2–4/1,000 babies”. The hearing capacity of a person is measured in dB or decibels. For a baby, this normally lies within a range of 0 to 20. If the hearing level of a baby is greater than 20 dB, this means that the baby has hearing loss. Depending on the level to which the hearing has been affected, it can be classified as mild, moderate, severe, and profound. It is important to understand that speaking loudly isn’t going to make any major impact as it is not just the volume but also the clarity that is compromised. Read to know 

How Hearing Loss Affects A Baby?

Hearing is the ability to perceive sounds and it is as important for a baby as it is for an adult. It is not only crucial for the development of spoken language but also for the various cognitive functions. It helps to stimulate the brain right from the time the baby is born, allowing it to form networks that help them to understand speech. Hearing loss can adversely affect these aspects, often resulting in a delay in speech. Some children are not able to speak at all. In the long run, this may negatively impact the child’s ability to interact, their behaviour, their education & social skills and lower their confidence. 

Types Of Hearing Loss In Babies

Conductive Hearing Loss In Babies

Conductive hearing loss is a condition triggered by the disruption in the movement of sound through the external or middle ear, preventing it from reaching the cochlea (the spiral, fluid-filled cavity present within the inner ear which helps us to hear). This can be due to a number of different reasons such as fluid accumulation behind the eardrum, excessive wax build-up or penetration of foreign objects into the ear canal. Surprisingly, the condition can be congenital too, which means that a baby is born with it. In such cases, it is caused by structural abnormalities in the small bones of the middle ear. In some cases, the problem resolves on its own as the child grows, however, others may need proper medical intervention to restore hearing. If that doesn’t work, a hearing aid may be recommended.

Sensorineural Hearing Loss In Babies

Sensorineural hearing loss is a permanent condition that results from damage to the fine hair lining the cochlea or the auditory nerve and is often linked to excessive exposure to loud noises and underlying genetic factors. Hearing loss is experienced after 30 to 50 percent of the hair is damaged. Congenital sensorineural hearing loss could be linked to genetic factors (in around 50 percent of the cases), environmental factors, infections, and oxygen deprivation. In the majority of cases, the condition does not improve with time. Early diagnosis and treatment are very crucial and it is usually managed with the help of a hearing aid.

What Increases The Risk Of Hearing Loss In Babies? 

There are certain factors that are known to put a baby at a higher risk of developing hearing loss. By identifying these factors and consulting a paediatrician or paediatric ENT specialist, necessary measures can be taken to alleviate the risks. The common risk factors include:

• If someone from the family, especially parents or siblings, has childhood sensorineural hearing loss (SNHL)

• If there are birth-related complications like severe neonatal jaundice requiring exchange transfusion or oxygen deprivation at the time of birth. 

• If the baby is born with a low birth weight 

• If the baby had to be admitted to the NICU for more than 5 days 

• If the mother had a severe infection during the course of pregnancy (like syphilis, rubella, herpes and toxoplasma. This is possible even if the mother is asymptomatic. 

• If the baby is born with facial malformations like cleft palate and microtia. 

• If the baby is born with conditions that can impact hearing, such as down syndrome

• Long term of certain medication that is not good for the baby’s ears

• If the baby has bacterial meningitis, a serious infection that damages the protective layer surrounding the brain and spinal cord. 

Symptoms Of Hearing Loss In Babies 

Babies with hearing loss can show symptoms that might be subtle or easy to miss. If you notice any of these symptoms in your baby, it's a good idea to talk to a paediatric ENT doctor. 

From The Time Of Birth To 4 Months Of Age 

• The baby does not react to any sound at 1 month

• The baby does not respond to their parent’s voice with smiles and coos, or by calming down

From 4 - 9 Months Of Age 

• The baby does not smile in response to your voice

• The baby doesn't seem to notice when toys make noise 

• The baby does not react by turning their head to familiar sounds

• The baby does not make babbling sounds 

From 9 - 15 Months Of Age 

• The baby is not babbling as much as expected 

• The baby is not attempting to repeat  or imitate simple sounds 

• The baby is not trying to communicate with you or grab your attention using sounds 

• The baby does not respond when you call their name 

From 15 - 24 Months Of Age 

• The baby is not using simple words like mama, dada  or baba to communicate

• The baby does not seem to enjoy listening to songs and rhymes 

• The baby is not able to identify common objects by their name

• The baby is not able to understand or recognize their body parts 

• The baby does not respond to simple commands or instructions

Hearing Milestones For Babies

Just like reaching other developmental milestones, achieving hearing milestones is crucial for a baby's overall growth and development. Here are some important milestones that you need to look out for: 

From Birth To 3 Months

• They will react to loud sounds with a startle reflex

• They will be comforted or calmed by your voice

• They will turn their head in your direction when you speak

• They will wake up from sleep if there is a loud sound 

• They will smile when spoken to by familiar people (parents, siblings, grandparents)

From 4 To 6 Months

• They will start turning their head to unfamiliar sounds 

• They will respond to the word ‘no’ or any change in the tone of your voice

• They will try to imitate their own sounds

• They like to play with toys that make sounds

• They start to make simple sounds like ‘ooh’, ‘aah’ and ‘baba’

• They get scared by loud noises and may even start crying

From 7 To 12 Months

• They will respond when called by their name. 

• They will respond to ringing phones and not-so-loud sounds.

• They will make babbling sounds even when no one is around.

• They will start paying attention to simple requests like ‘Come here’ 

• They will start looking at objects that you talk about

• They will react to and enjoy interactive games like peek-a-boo.

• They will try to copy simple words and sounds you make. 

From 1 To 2 Years

• They follow 1 step commands shown through gestures. 

• They frequently use words that they have learned.

• They will try to make short sentences, even if they are not meaningful.

• They will add more words and terms to their vocabulary.

• They are able to identify and point towards various body parts.

• They are able to understand and respond to simple questions and phrases like ‘Are you hungry?’, ‘on the table’ and so on

• They enjoy storytelling and may want you to read to them.

• They understand and respond to multi-step instructions like ‘get the ball and sit here’

What Is Newborn Hearing Screening?

Newborn Hearing Screening refers to the early assessment of a baby’s hearing, soon after they are born. The best time to do it is before being discharged from the hospital and it is recommended for all babies, even those without any risk factors. An otoacoustic emission (OAE) test is performed to evaluate the functioning of a baby's inner ear or cochlea.

High-risk babies may not necessarily present with the symptoms of hearing loss at the time of birth and the problem may manifest later. Hence it is advisable to go for re-screening, every 3 months. 

When Should You Go For A Newborn Hearing Screening?

As per the ‘Consensus Statement of the Indian Academy of Pediatrics on Newborn Hearing Screening’, it is recommended “First screening should be conducted before the neonate’s discharge from the hospital – if it ‘fails’, then it should be repeated after four weeks, or at first immunisation visit. If it ‘fails’ again, then Auditory Brainstem Response (ABR) audiometry should be conducted. All babies admitted to intensive care units should be screened via ABR. All babies with abnormal ABR should undergo detailed evaluation, hearing aid fitting, and auditory rehabilitation, before six months of age. The goal is to screen newborn babies before one month of age, diagnose hearing loss before three months of age, and start intervention before six months of age.”

Importance Of Newborn Hearing Screening

It is crucial to identify hearing loss in babies at the earliest. Indian Academy of Pediatrics (IAP) suggests, “The critical period for identification and remediation of hearing loss is before the age of 6 months.” 

Further, “Since the paediatrician is the primary care provider for the child during the first few days of life, it is the sole responsibility of the paediatrician (or the primary physician) to evaluate the child for hearing loss (or ensure referral for the same). It has been observed that the practice of neonatal screening has dramatically lowered the age of diagnosis of deafness from 1½ - 3 years to less than 6 months of age.”

Early screenings help to identify hearing loss at an early stage, thereby alleviating the risks of the baby losing their ability to speak as well. 

Newborn Hearing Screening In India

The Child Health Screening and Early Intervention Services Program (Rashtriya Bal Swasthya Karyakram) under the National Rural Health Mission initiated by the Ministry of Health and Family Welfare of the Government of India has listed congenital deafness among the conditions that require early identification and remediation. In order to improve the management of hearing disabilities, mobile teams have been set up for screening infants and children below 18 years of age and proper treatment facilities are provided with the help of dedicated District Early Intervention Centers (DEICs).

Sources:

https://www.indianpediatrics.net/aug2017/647.pdf 

https://iapindia.org/pdf/Ch-025-Hearing-IAP-Parental-Guideline.pdf  

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4689099/ 

About The Author

Dr. Vivek Gogia is a highly skilled and renowned ENT expert with extensive international training and 15 years of advanced surgical experience. His areas of specialisation include ENT/ Otorhinolaryngology, Pediatric Otorhinolaryngology, and Head & Neck Surgery. He earned his MBBS degree from Maulana Azad Medical College (New Delhi) and pursued his Masters (MS) in ENT from University of Delhi. He completed DNB-ENT from National Board of Examination and Oman Medical specialty Board (OMSB-ENT) from Ministry of Health, Oman. Dr. Vivek has completed his MRCS (UK) from the Royal College Of Surgeons, England. He gained experience as a Senior ENT surgeon at the University Hospitals of Morecambe Bay for around two years. During his time in the UK, he refined his surgical skills in rhinoplasty at the University of Dundee, Scotland. Additionally, he received training in stapes surgery in France and cochlear implants in Austria.