What is the difference between different kind of hearing aids, processors and assistive listening devices.
Hearing aids best help people with a mild to moderate hearing loss.
Basically a hearing aid amplifies sound. The microphone(s) on the hearing aid pick up the speech and sounds in your environment, makes them louder and then sends the sound acoustically through to your ear drum and middle ear to the cochlea (ie just the way hearing people hear). How well you will hear the amplified sound depends on the damage your ear has. If your middle ear can’t conduct the sound then what reaches your cochlea will be distorted. If your cochlea has damaged cells then even though you receive the full sound you still will hear only parts of it.
HEARING AID kinds
SIZE SHAPE AND WAY OF WEARING
EAR TRUMPET– I believe Queen Victoria used one -[Cupping your hand behind your ear works much the same way – you’ve probably seen people do it]
BODY WORN – Consists of a box worn in a pocket which amplifies the sound and a cord up to your ear sends you sound. This is old technology these days and not many people still wear them.
HEARING AID GLASSES – A hearing aid which is built into a glasses frames so that someone who needs glasses doesn’t have two things behind their ear. Not terribly popular but still available.
BEHIND THE EAR (BTE) – a hearing aid which is worn behind your ear with a plastic tube and often an ear mould in your ear to convey the sound to your ear canal. Because they were bigger, these used to provide stronger amplification than ‘in the ear aids’ but with Digital technology this is no longer the case.
IN THE EAR hearing aids – a hearing aid which is worn in the ear. These were often moulded to the same shape as your ear canal. With digital technology these can be so small as to almost be invisible. In the ear aids also come in disposable versions. The hearing aid is ‘implanted’ in the ear canal and left in for up to a month, then removed and replaced.
IN THE DRAWER hearing aids – most profoundly deaf people have a few of these. These are hearing aids which we’ve been prescribed but which give us so little benefit that we leave them in the drawer.
HEARING AID TECHNOLOGIES
ANALOGUE HEARING AIDS – this type of technology is pretty much finished. There was limited capability for programming to an individual’s hearing needs and basically they amplified sound and nothing else. They came in any size and way of wearing.
DIGITAL AIDS – these are becoming the norm and allow the audiologist to program to specific hearing needs. For instance if someone can’t hear high frequencies, the hearing aid can be programmed to lower these frequencies into a range the wearer can hear. I believe it takes a bit of getting used to. They are usually small and discreet – often they have a remote control to allow the wearing to program for specific circumstances without the need to reach for their ear. Mostly these are very small BTE aids or In the Ear aids.
IMPLANTABLE HEARING SOLUTIONS
For people who have profound to severe sensorineural deafness a Cochlear Implant may be an alternative.
With surgery to implant the receiver, when the processor is worn we totally deaf people can hear.
What the processor does is actually change sound into electrical impulses which are conducted by the implant to the cochlea and stimulates the hearing nerve directly by-passing the damaged cells. For me and many people like me the implant returns near normal hearing.
BAHA Hearing aid
A Baha hearing aid (Bone Conducted Hearing Aid) helps those people who have ear, canal or middle ear problems (ie conductive problems) but still have an intact cochlea. The Baha picks up the sound and creates the sound vibration conducting it through the skull into the cochlea. People with this kind of hearing loss report the Baha gives them near normal hearing. This is often useful for people with single sided deafness. The Baba uses a small surgically implanted titanium pin to attach the processor to.
HYBRID COCHLEAR IMPLANT
This is a smaller internal cochlear implant which saves some of the residual hearing. The person who uses this type of implant still has low frequency hearing which can be aided with a hearing aid. So a hearing aid is attached to the external implant processor and conveys sound acoustically to the cochlear in the lower frequencies.
ASSISTIVE LISTENING DEVICES
These should not be confused with hearing aids. These devices may help people who have a mild hearing loss and do not wear hearing aids but may also be helpful for people who wear aids or processors.
They are things like
-hearing loops put into cinemas and auditoriums so people who wear hearing aids or processors can switch to a telecoil function and have the sound sent via a radio or FM frequency to their hearing aid.
-adaptors and amplifiers for telephones so anyone form a mild hearing to profound loss can hear etc.
-Devices which also fall into this category which aren’t really listening devices are things like Shake Awake alarms (which can be linked to a telephone, fire alarm or clock alarm). Cords which can be plugged into a hearing aid or processor and directly plugged to a media device (headphones, audio cords etc)
For more detail about any of these solutions links to specific articles may help you.