There are several other types of hearing aid that help people with conditions where normal hearing aids won't work. These include Bone Anchored hearing aids, Bone Conduction hearing aids, CROS and BI-CROS hearing aids and Cochlear implants.
Bone-anchored Hearing Aids:
Bone-anchored hearing aids are actually a type of bone conduction hearing aid. The difference is that they require an implant in the bone of the skull behind your ear. It then connects to a small case with a microphone and a sound processor.
Who can benefit from a bone anchored hearing aid?
Bone anchored hearing aids are a breakthrough technology that allows people with hearing problems, who cannot benefit from the regular hearing aids to alleviate their hearing impairment. A bone anchored hearing aid might be suitable in the following cases:
- chronic ear infections that cause excessive ear drainage,
- damage of the drum or the middle ear,
- conductive hearing loss,
- hearing in one ear only (unilateral hearing loss),
- mixed hearing losses,
- external ear canal problems,
- and malformations (e.g. narrow ear canal).
Bone Anchored hearing aids are designed to improve speech understanding and reduce feedback and the sound distortion. The ear canal is open, creating comfort and a natural perception of sound. Bone Anchored hearing aids are sometimes substituted for CROS hearing aids. They transmit the sound from the good ear via vibrations, thus creating a feeling of hearing with the impaired ear.
What is a Bone Anchored hearing aid?
As the Bone Anchored hearing aid acts as a Bone Conduction hearing aid, it transmits the signal via vibrations in the skull to the inner ear and bypasses the middle ear entirely. It has three components, which include a titanium implant (prosthesis) and a sound processor situated on an external abutment. The operation places a titanium implant in the skull and with time, it gradually integrates with the bone. The sound processor picks up the sound vibrations and transmits them to the implant making the skull bones vibrate. These vibrations reach the inner ear and allow the wearer to hear.
The surgical procedure for implanting the titanium part is not complex. It takes up to six weeks after that for the audiologist to place the hearing processor and adjust it for the particular hearing loss level.
The surgery and placement of the bone anchored hearing aid inside the skull bone is not a complicated procedure. Although there are a number of issues you should take into account when having such a hearing aid. It is very important to provide daily care for the skin around the implant to avoid infections and inflammations – it is best for that area to be free of hair follicles. In addition, you should be careful with the external sound processor as it is delicate and can be damaged easily.
Although a bone anchored hearing aid is a widely used solution for people with hearing impairment that cannot be helped by regular hearing aids, not everyone that can benefit from this technology is suitable for it. The patient's skull must have a particular thickness. This is why small children cannot have this surgery, as their skull is thinner and softer than an adults.
As this is a surgical procedure, the first part of the process is to have a series of consultations with a qualified audiologist and surgeon. Consult your GP initially who will screen you and refer you for further consultations where necessary to determine cause and suitability.
Bone Conduction Hearing Aids:
Another type of hearing aid used for unilateral hearing loss is the bone conduction hearing aid. This transfers the sound from the ear with hearing loss to the normal ear through the bone. Bone Conduction hearing aids can either be body worn or fitted in a headband. The bone conductor receives sound from the microphone and vibrates to mimic the sound waves which the ear would normally receive.
Their main advantage is that they leave the ears open, which is very beneficial for people who are susceptible to frequent ear infections.
CROS & BiCROS Hearing Aids:
These types of hearing aids are suitable for people who have a severe hearing loss only in one ear. Usually you would wear two hearing aids similar to behind the ear hearing aids. The device that sits in the deaf ear has a microphone that picks up the sound. It transmits the sounds it receives wirelessly to the device in the other ear.
If your non-deaf ear has some degree of hearing loss then you would have BiCros hearing aids. In this case, the hearing aid in the hearing ear also amplifies the sound received.
The main advantage of these hearing aids is that you can hear sounds coming from your deaf side which you would normally miss.
The Phonak Cros ITE is an example of an in the ear Cros hearing aid.
Cochlear implants work by turning sound into electrical signals and sending them to the cochlear in the inner ear. From here, the signals travel to the brain and you hear them as sound.
About Hearing Direct
We are one of the world's leading hearing aid specialists. HearingDirect offers a wide range of affordable products, and information resources to help improve the quality of life for the hard of hearing.
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- and amplified devices such as super loud alarm clocks and amplified phones.
Author: Joan McKechnie
After qualifying as a Speech-Language Pathologist and Audiologist Joan has spent most of her 20 year career in hearing-care related roles. She has a wealth of experience within the hearing aid and hearing rehabilitation fields and has worked in manufacturing environments with two hearing aid companies helping to develop products and roll out new technologies. Joan has been involved with Hearing Direct since its launch and enjoys the online retail environment which seeks to provide easier access to hearing products and accessories. She is HCPC registered. Read Joan's full bio here.