What are the effects and signs?
Mild deafness
Within this range a hearing aid may be required depending upon the frequencies affected by the hearing loss and whether the child has a dual sensory disability. They will be unlikely to require communication aids, or use manual communication (BSL) unless they have a co-existing condition (e.g. Down’s syndrome). A child with mild deafness will hear conversation one-to-one in quiet background conditions. However they will find it difficult to follow speech in situations where there is a lot of background noise and over distance (e.g. they will be unable to hear the teacher from the back of a classroom or someone calling across an outdoor space).
Hearing Loss in one ear
Unilateral hearing loss (hearing impairment of one ear only), regardless of how severe the level of hearing loss is, should not normally affect the ability to perform normal day to day activities appropriate to the child’s age.
Moderate deafness
A child with moderate deafness finds it difficult to follow speech without a hearing aid or other technology to amplify sound. The child may lip read and therefore finds it harder to follow speech when not one-to-one even with hearing aids in.
They are likely to gain benefit from amplification either from a hearing aid or by external devices. They may rely on a combination of amplified sound and lipreading. They will usually have speech that can be understood by strangers and will be able to hear and understand a normal voice at I metre with appropriate amplification. Background noise will have a notable affect in understanding speech.
Severe and profound deafness
A child with severe or profound deafness will probably lip read and may use sign language. When hearing aids are not powerful enough for the child they may be fitted with a cochlear implant (a specialist hearing device surgically implanted into the inner ear).
A few children are deaf because they were born without a cochlea (inner ear) or hearing nerve. In these cases the child will have no hearing at all and will not benefit from amplification devices. These children will communicate using sign language. They may be eligible for a brainstem implant, but this is rarely carried out. Speech may be affected such that they may not be understood clearly by strangers.
Hearing aids and cochlear implants do not restore hearing to normal levels. They use microphones which have a limited pick up range and may amplify extraneous background noise as well as speech. Deaf children may use a variety of other equipment to complement their prescription hearing aids or cochlear implants e.g. text phone, loop systems etc.
Indicators of severe functional restriction
Children with a severe functional restriction are likely to:
- Have Hearing loss of 71dB or more with or without hearing aids/cochlear implant
- Rely on text rather than speech when using phones
- Use manual communication if the onset of hearing loss was before the development of language skills (prelingual deafness)
- Be eligible for a cochlear implant
- Be unable to hear and understand a raised voice at 1 metre with or without hearing aids/cochlear implant
- Have speech affected such that they may not be understood clearly by strangers
- Have a medical condition making use of hearing aid or cochlear implant impossible (e.g. absent or severely deformed cochlea or hearing nerve, Auditory Neuropathy Spectrum Disorder)
Vestibular hypofunction
The majority of children with profound hearing loss have vestibular hypofunction (inadequate function of the body’s balance system). Some children with severe hearing loss and occasionally children with moderate hearing loss also have vestibular hypofunction.
Vestibular hypofunction may cause early delay in gross motor development though children tend to catch up, usually by age 5. They have a delay in walking, the mean age for walking being 18 months compared with12 months for a normal child.
It affects the ability of children to right themselves if they are off balance and as a result they are more likely to fall. They may have difficulty walking over rough terrain or in low light conditions.
