How is it treated and managed?
Conductive hearing loss
Bone-conduction or surgically implanted Bone Anchored Hearing Aids can be used in specific circumstances. Sometimes surgical interventions may be offered as treatment for glue ear (insertion of grommets), otosclerosis (stapedectomy) and perforated tympanic membrane (myringoplasty or tympanoplasty).
Sensorineural hearing loss
This is usually managed by the use of hearing aids. Surgically implanted devices such as Cochlear Implants or Middle Ear Implants may be used in specific circumstances.
Aids for Improving Hearing
Hearing aids
Hearing aids are devices that amplify sounds. They can be used in both conductive and sensorineural hearing loss. Their use usually improves a child’s hearing to the level of the speech frequencies so that they are able to hear conversation one-to-one and in small groups. Hearing aids do not return hearing to the normal ranges and additional tactics may be needed in noisy situations (e.g. lipreading) and when listening at a distance. Children who are severely to profoundly deaf bilaterally who get limited or no benefit from conventional hearing aids may be fitted with a cochlear implant. Hearing aids last 5 years on average, and in the UK all children obtain them free from the NHS. Rarely, they have privately purchased hearing aids from a registered Hearing Aid Dispenser.
There are occasions when a hearing aid may not be worn, for example when the child is in the bath or when swimming.
The hearing aid consists of -:
- A microphone to pick up sound signals
- A battery powered amplifier to amplify sound signals
- A receiver to deliver the amplified sound to the ear canal
Digital aids are programmable to individual hearing requirements. The settings can be controlled to match the hearing loss frequency only, thereby limiting amplification of background noises. The benefit is limited in real life situations. Many digital hearing aids are designed to reduce steady kinds of background noise, such as the rumble of traffic or the whirr of a fan. This can make listening more comfortable, but it does not necessarily enable the user to pick out a single voice from everything else going on, especially when several people are talking at once. Directional microphone systems amplify sounds that come from in front of the person more than sounds to the side or behind them. This makes it easier for the person to focus on what they want to listen to in a noisy place but means they will not hear a call from behind. The user can switch between directional and all round sound, depending on what they need to hear at the time. Some digital aids will detect where the noise is coming from and automatically adjust to reduce the noise selectively. However, a hearing aid cannot know what the person wants to listen to. Directional hearing remains a problem for many hearing aid users.
They are customized to the person, and are normally available in the “behind the ear” style, on the NHS.
Hearing aids require reasonable care and cleaning and are powered by dry batteries which need replacing from time to time. There are a number of precautions that parents may take to prevent children getting hold of batteries, such as child proof battery locks that can be fitted by an audiologist.
Children under 3 years - Hearing aids are not “baby safe” and there is a risk of choking on the soft components, such as tubing and ear moulds. Therefore supervision will be needed for children under 3 years who wear a hearing aid and carers are advised to remove the hearing aid(s) if the child is to be left alone even for a brief period of time.
Children between the ages of 3 and 8 years - If a child has a history of pulling out or switching their hearing aid(s) off, carers are advised to be vigilant and check the hearing aid(s) at least every 30 minutes during the day.
At night time - Carers are advised to take hearing aid(s) out at night. Occasionally a child becomes distressed when the hearing aid is removed and in this case, carers are advised to wait until the child falls asleep before removing the aid(s).
Cochlear Implants
Cochlear Implants are surgically - implanted devices, which directly stimulate the auditory nerves in the cochlea.
Children with severe and profound sensorineural hearing loss who have not benefited from a trial of hearing aids are usually referred to a specialist cochlear implant team for assessment.
There are a number of factors that are taken into consideration before a child is offered a cochlear implant. These include -:
- Hearing. Is the hearing loss severe to profound and are hearing aids insufficient?
- Age. In children who are born deaf, the acquisition of speech and language is related to the age at which cochlear implantation takes place. The best results are obtained in children who receive a cochlear implant before the age of two years. In one study, 90% of children who received a cochlear implant below the age of 2 years entered mainstream education; 60% for implantation between age 2 and 4 years; and 20% for those after the age of 4. The maximum age for implantation is considered to be around the age of five years for those born deaf although those with acquired and progressive deafness can be implanted later in life.
- Stable family support is required because of the need for cooperation of the child’s carers in a long term rehabilitation programme.
- Absence of medical contraindications to surgery such as chronic ear infections or abnormal inner ear anatomy.
After implantation, children require a few years of rehabilitation to teach them to listen to and make sense of the new sounds and to optimally tune the device. Most children are eventually able to hear conversation without lip reading and use spoken language for everyday communication.
Bone conduction hearing aids
Bone conduction hearing aids may be given to children who have a conductive deafness. The hearing aid vibrates in response to sounds going into the microphone and the vibrations are transmitted to the cochlea through the bones in the skull.
Bone anchored hearing aids
Bone Anchored Hearing Aids are surgically implanted devices that transmit sound directly to the inner ear through the bones of the skull and can be suitable for children with a permanent conductive hearing loss who have already tried a bone conduction aid. They tend to be more comfortable and give a better sound quality than bone conduction aids.
Middle Ear Implants
A middle ear implant (MEI) is essentially a hearing aid, but one in which the receiver or the entire hearing aid is surgically implanted into the middle ear. Unlike cochlear implants, MEIs are designed for people with significant residual hearing. They have a number of advantages over conventional hearing aids. These include elimination of acoustic feedback, avoidance of the need to insert an earpiece in the ear canal and improved cosmetic appearance. MEIs are currently rarely used in children.
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