Discovering that a child has hearing loss is often the beginning of a process that feels uncertain and fast-moving. A referral from the newborn hearing screen, a GP concerned about speech development, or a teacher who notices a child straining to hear: however it surfaces, the path from suspicion to diagnosis usually moves quickly, and families benefit from understanding what they're navigating.
Hearing loss in childhood is more common than most parents realise, and the outcomes for children identified and supported early are genuinely good. The earlier a child gets appropriate support – hearing technology, communication input, and language exposure – the smaller the gap in language development, and the better the educational and social outcomes.
Healthbooq (healthbooq.com/apps/healthbooq-kids) covers childhood development and health.
How Common Hearing Loss Is
Around 1 in 1,000 babies is born with permanent hearing loss in one or both ears significant enough to affect language development. An additional 1 in 1,000 acquires hearing loss during childhood from causes including meningitis, cytomegalovirus (CMV), ototoxic medications, or progressive genetic conditions. By school age, around 2 in 1,000 children have permanent hearing loss.
Temporary hearing loss from glue ear (otitis media with effusion) is much more common – affecting around 80% of children at some point – but this is categorised separately because it usually resolves.
The Two Main Types
Conductive hearing loss involves the outer or middle ear: sound is not being conducted efficiently to the cochlea. The most common causes include glue ear, perforation of the eardrum, or problems with the ossicles (the tiny bones in the middle ear). Conductive hearing loss is often, though not always, treatable or correctable.
Sensorineural hearing loss (SNHL) involves the inner ear (cochlea) or the auditory nerve. It reflects permanent damage to or absence of the hair cells of the cochlea that convert sound vibrations into electrical signals. SNHL is the more common type for congenital permanent hearing loss. Around 50% of congenital SNHL has a genetic cause (the most common single gene being GJB2/connexin 26), 20-25% has an environmental cause (CMV being the most significant, discussed below), and around 25% remains of unknown cause after full investigation.
Mixed hearing loss has components of both conductive and sensorineural.
Unilateral hearing loss (in one ear only) affects around 1 in 1,000 children. It is sometimes missed by the newborn screen (which is done one ear at a time) and may surface later. Children with unilateral hearing loss have greater difficulty than those with normal bilateral hearing in noisy environments and localising sound, and they have higher rates of educational difficulty than children with normal hearing, making early identification important.
The Newborn Hearing Screen
The NHS Newborn Hearing Screening Programme, introduced across the UK progressively from 2001, uses automated otoacoustic emissions (AOAE) testing. A small probe placed in the ear canal emits clicks and detects the faint sounds (otoacoustic emissions) produced by the healthy cochlea in response. The test takes a few minutes and can be done when the baby is asleep.
A "refer" result – where the expected response is not detected – means the test needs to be repeated, not that the baby has a hearing loss. Many "refer" results are caused by fluid in the ear canal after birth or background noise, not hearing loss. If the refer result persists on repeat testing, the baby is referred to the local audiology service for further assessment, usually within four weeks.
NICU babies are tested with automated auditory brainstem response (AABR) testing instead of AOAE, because AOAE does not detect auditory neuropathy spectrum disorder (ANSD), which affects some NICU infants.
Despite the newborn screen, around 40% of children with hearing loss are not identified at newborn screening – either because the loss was missed, because it is progressive, or because it develops after the newborn period. Any parent or professional concerned about a child's hearing should request audiology assessment regardless of the newborn screen result.
Signs of Hearing Loss Beyond the Newborn Period
In infants: not startling to loud sounds; not responding to their name by 9-12 months; not turning towards voices or environmental sounds; quieter than expected (fewer babbles, less varied vocalisations).
In toddlers: late speech development (fewer than 50 words by age 2, not combining words by 2.5); saying "what?" frequently; not following simple instructions; speech that is difficult to understand.
In school-age children: difficulty hearing in noisy environments; frequently mishearing words; appearing to not listen or not follow instructions; academic difficulties; sitting close to the television or turning it up loud.
Assessment and Diagnosis
Audiological assessment in young children requires age-appropriate test techniques. In the first months of life, AABR testing (or more detailed auditory brainstem response – ABR) is used, measuring electrical responses in the brainstem to sounds. From around 6-7 months, visual reinforcement audiometry (VRA) is used: the child is conditioned to turn their head in response to sounds, and a moving toy rewards the correct response. From around 2.5-3 years, play audiometry (pointing to toys in response to sounds) is used. Older children can cooperate with conventional pure-tone audiometry.
An audiogram (graph of hearing thresholds at different frequencies) is the primary tool for describing hearing. Results are described by the degree of loss:
Mild: 25-40 dB HL (decibels hearing level). Quiet conversations may be missed; consonants can be hard to distinguish.
Moderate: 40-70 dB HL. Normal conversation difficult without hearing aids.
Severe: 70-95 dB HL. Only loud speech heard without hearing aids.
Profound: 95 dB HL or more. Little or no audible speech without cochlear implants.
Hearing Aids
Hearing aids are the primary intervention for mild to severe hearing loss. Modern digital hearing aids are highly effective for most sensorineural hearing losses; they amplify sound, with sophisticated processing to emphasise speech frequencies. In the UK, all NHS hearing aids are free. Children typically receive behind-the-ear (BTE) hearing aids with moulds that fit the ear canal; moulds need replacing every few months as children grow.
The effectiveness of hearing aids depends substantially on how consistently they are worn – which is a challenge with young children who remove them. Supporting consistent use, particularly in the first years of life when language development is most sensitive to auditory input, is one of the central tasks of families and professionals in this area.
Radio aids (FM systems and digital sound field systems) are used in classroom settings to transmit the teacher's voice directly to the child's hearing aid, cutting through background noise. They are significantly beneficial for children with hearing loss in educational settings and should be considered for all school-age children with permanent hearing loss.
Cochlear Implants
For children with severe or profound SNHL who do not gain adequate benefit from hearing aids, cochlear implants are the most effective intervention. A cochlear implant bypasses the damaged hair cells of the cochlea and directly stimulates the auditory nerve with electrical signals, allowing the brain to process sound.
In the UK, cochlear implantation for children is provided at specialist implant centres. NICE guidelines recommend cochlear implants for children with severe to profound SNHL in both ears who do not benefit sufficiently from well-fitted hearing aids. Bilateral implantation (both ears) is recommended in children, as it significantly improves sound localisation and hearing in noise compared with unilateral implantation.
The outcomes from cochlear implantation depend heavily on the age at implantation. Research by Richard Dowell at the University of Melbourne, and by teams at the Manchester and Great Ormond Street cochlear implant centres in the UK, has consistently shown that children implanted before 18-24 months of age have significantly better speech and language outcomes than those implanted later, reflecting the critical period for auditory cortical development. This is why early identification through newborn screening is so important for this outcome.
Communication and Language
Families of deaf children face choices about communication approach that can feel high-stakes. The main options are oral/auditory approaches (using spoken language supported by hearing technology), sign language (British Sign Language in the UK), and combined approaches (total communication). There is no single right answer, and the appropriate approach depends on the degree of hearing loss, the child's cochlear implant outcomes, and the family's communication preference.
BSL is a complete, complex, grammatically distinct language from English, not a signed version of English. Children who are exposed to BSL from birth develop language at the same rate as hearing children exposed to spoken language. NDCS supports families in understanding all communication options without prescription.
The National Deaf Children's Society (NDCS) provides advice, helpline support, and resources for families at every stage. Their website and family services team are the most useful starting point for newly diagnosed families in the UK.
Key Takeaways
Around 1 in 1,000 babies is born with permanent hearing loss significant enough to affect language development, and a further 1 in 1,000 acquires it during childhood. The NHS Newborn Hearing Screening Programme identifies most congenital cases before three weeks of age. There are two main types of hearing loss: conductive (affecting the outer or middle ear, often treatable) and sensorineural (affecting the inner ear or auditory nerve, usually permanent). Early identification and intervention – hearing aids, cochlear implants, speech and language therapy – significantly improve language and educational outcomes. The National Deaf Children's Society (NDCS) is the main UK charity providing support and advocacy for deaf children and their families.
