There is help for patients with all types of hearing loss. Treatment depends on why the deafness exists and how severe it is.
Sensorineural hearing loss is incurable. When the hair cells in the cochlea are damaged, they cannot be repaired. However, various treatments and strategies can help improve the patient’s quality of life.
Scientists from the University of California, San Francisco, reported in July 2012 that congenital hearing loss can be reversed in a mouse model. They hope their research will eventual lead to gene therapy for humans.
Hearing aids
These are devices that help in hearing. There are several types of hearing aids; they come in a range of sizes, circuitries and levels of power. They do not cure deafness, but amplify the sound that enters the ear so that the listener can hear things more clearly.
Hearing aids consist of a battery, loudspeaker, amplifier and microphone. Today they are very small, discreet and can be fitted inside the ear. Many of the modern ones can distinguish background noise from foreground sounds, such as speech.
For a person with profound deafness, a hearing aid is not suitable.
The audiologist takes an impression of the patient’s ear to make sure the device fits well. It will be adjusted to the patient’s auditory requirements.
Examples of hearing aids include:
Five common types of hearing aids
- Behind-the-ear (BTE) hearing aids – these consist of a dome (earmold) and a case, with a connection from one to the other. The case is behind the pinna (outer ear, the part that sticks out); the connection to the dome comes down the front of the ear. The sound from the device is routed to the ear either electrically or acoustically.
- BTE hearing aids tend to last longer than other devices because the electrical components are located outside the ear (less moisture and earwax damage). These devices are more popular with children who need a sturdy and easy-to-use device.
- In-the-canal (ITC) hearing aids – these fill the outer part of the ear canal and can be seen, but only just. Soft ear inserts, usually made of silicone, are used to position the loudspeaker inside the ear. These devices fit most patients straight away, and have better sound quality.
- Completely-in-the canal (CIC) hearing aids – these are tiny devices, but are not recommended for people with severe hearing loss.
- Bone conduction hearing aids – for patients with conductive hearing loss, as well as those unable to wear conventional type hearing aids. The vibrating part of the device is held against the mastoid with a headband. The vibrations go through the mastoid bone, to the cochlea. These devices can be painful or uncomfortable if worn for too long.
Cochlear Implants
The external parts of a left-ear cochlear implant
Inserted to help patients whose hearing impairment is caused by hair cell damage in the cochlea. The implants usually help most people understand speech better. The latest cochlear implants have new technology which helps patients enjoy music, understand speech better even with background noise about, and use their processors while they are swimming.
According to the National Institutes of Health, about 42,600 adults and 28,400 children had cochlear implants in the USA in 2010. The World Health Organization says approximately 219,000 people globally are recipients, most of them in industrial countries.
A cochlear implant consists of:
External:
- A microphone that gathers sound from the environment (may be more than one)
- A speech processor which prioritizes sounds that matter more to the patient, such as speech. The electrical sound signals are split into channels and sent through a very thin wire to the transmitter
- A transmitter. This is a coil which is secured with a magnet. It is located behind the outer hear. It transmits the processed sound signals to the internal implanted device
Internal:
- A surgeon secures a receiver and stimulator in the bone beneath the skin. The signals are converted into electric impulses and sent through internal wires to the electrodes
- Up to 22 electrodes are wound through the cochlea. The impulses are sent to the nerves in the Scala tympani, and then directly to the brain. The number of electrodes depends on which company makes the implant.
Children will usually have cochlear implants in both ears, while adults tend to have one in just one ear.
Recent developments in hearing loss from MNT news
Could a vitamin supplement prevent hearing loss?
Noise-induced hearing loss is associated with damaged synapses that connect the nerves and hair cells in the cochlea – a part of the inner ear. But a new mouse study suggests noise-induced hearing loss can be prevented with a simple chemical compound that protects the nerves that stimulate the cochlea.
Are faulty mitochondria to blame for hereditary hearing loss?
No fewer than 95 genes have so far been implicated in hearing loss. A new study into mitochondrial activity may open new and exciting avenues of research into potential gene therapies.
Sign language and lip-reading
Some people with hearing impairment may have speech problems, as well as difficulties in understanding what other people say. A high percentage of people with hearing impairment can learn other ways of communicating. Lip reading and sign language can replace or complement oral communication.
Lip reading (lipreading)
Also known as speechreading, lip reading is a method for understanding spoken language by watching the speakers lip, facial and tongue movements, as well as extrapolating from the data provided by the context and any residual hearing the patient might have.
People who became hearing impaired after they learnt to speak can pick up lip reading rapidly; this is not the case for those who are born hearing-impaired.
Sign language
This is a language that uses signs made with the hands, facial expressions and body postures, but no sounds – it is used mainly by those who are deaf. There are several different types of sign languages. British sign language is much more different from American sign language than British and American spoken English. British sign language uses a two-handed alphabet, unlike American Sign Language.
Some countries use the sign language introduced by missionaries from faraway – Norwegian sign language is used in Madagascar.
Sign language is completely different from the spoken form, word order (syntax) and grammar in British sign language is not the same as it is in spoken English. American Sign Language is more grammatically similar to spoken Japanese than spoken English.
Can hearing impairment be prevented?
There is nothing we can do to prevent congenital deafness (when you are born with the condition), or hearing impairments due to illnesses or accidents. However, some measures can be taken to reduce the risk of losing some of your sense of hearing.
The structures in our ears can be damaged in several different ways. Long term exposure to very loud noise – above 85dB can eventually cause hearing loss. A typical lawn mower emits about 85dB.
The following measures may help protect your hearing:
- TV, radio, music players and toys – do not set the volume too high. Children especially are very sensitive to the damaging effects of loud music. Researchers found that noisy toys put children’s hearing at risk.
- Headphones – focus on isolating what you want to hear; block out all outside noise as much as possible, instead of drowning it out with high volume.
- The workplace – if you work in a noisy environment, wear ear plugs or ear muffs. Even in discos, nightclubs, and pubs – ear plugs are discreet and hardly noticeable.
- Leisure venues – if you go to pop concerts, motor racing, drag racing and other noisy events, wear ear plugs.
- Cotton swabs (UK cotton buds) – do not prod them into your or your children’s ears. The same applies for cotton or tissues.
References
- Elsevier, Dorland’s Illustrated Medical Dictionary, Elsevier
- “Deafness”. Encyclopædia Britannica Online. Encyclopædia Britannica Inc. 2011. Retrieved 2012-02-22.
- “Deafness and hearing loss Fact sheet N°300”. March 2015. Retrieved 23 May 2015.
- Lasak, JM; Allen, P; McVay, T; Lewis, D (Mar 2014). “Hearing loss: diagnosis and management.”. Primary care 41 (1): 19–31. doi: 1016/j.pop.2013.10.003. PMID24439878.
- “1.1 billion people at risk of hearing loss WHO highlights serious threat posed by exposure to recreational noise” (PDF). who.int. 27 February 2015. Retrieved 2 March 2015.
- “About Hearing Loss”. Centers for Disease Control and Prevention. Retrieved 2016-07-15.
- National Institute on Deafness and Other Communication Disorders (NIDCD) (2013). Hearing Aids. Retrieved from http://www.nidcd.nih.gov/health/hearing/pages/hearingaid.aspx
- “Auditory Sciences”. Auditory Sciences.