DdEF Glossary
"When I use a word, "Humpty Dumpty said in rather a scornful tone, "it means just what I choose it to mean – neither more nor less." Lewis Carroll
Welcome to the DdEF site's glossary page. If you're not familiar with issues around deafness and hearing loss, some of the words can be confusing. All around the web site words highlighted in bold are explained on this glossary page. On each page of the site, as well as the directions sign that you can click on to go to the site's site map, you'll also see the ‘question mark’ sign. Clicking on that sign from any page on the site will bring you to here, the glossary page.
Clicking on a letter below will take you to be beginning of the section that has word beginning with that letter. From there the words are arranged alphabetically. You can go back to the page you were last viewing by either using the ‘back’ button on your browser, or clicking any of the Back to previous page links.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Access to Work: a government scheme that helps people with disabilities to find or stay in work, providing financial support towards adjustments or equipment to enable a disabled person to work, and towards transport costs.
acoustic nerve: another name for the auditory or vestibulocochlear nerve.
acoustic trauma: occurs when you are exposed to a very loud noise for a short period of time, for example, if you're close to an explosion or gunfire. This can cause a sudden hearing loss that is worst in the ear closest to the sound. It is usually a sensorineural hearing loss, though in some cases a very intense sound can perforate your eardrum.
anvil: another name for the incus bone.
ASL: American Sign Language (see BSL).
audiologist: a health care professional who is a specialist trained in the evaluation and testing of hearing and hearing loss and related disorders.
auditory nerve: the eighth cranial nerves, also known as the vestibulocochlear nerve. It is the nerve along which the hair cells of the inner ear transmit information to the brain. It is made up of the cochlear nerve, carrying information about hearing, and the vestibular nerve, carrying information about balance. The auditory nerve is also known as the acoustic nerve.
B
Benefits Agency: deals with state benefits, including disability and health related benefits. You can find the address and telephone number of your nearest Benefits Agency office in the telephone directory.
BSL: British Sign Language – the sign language used in the UK. BSL is the first or preferred language of nearly 250,000 deaf and hard-of-hearing people in the UK. It is a language of space and movement using the hands, body, face and head. BSL is a complete language in it's own right, having a structure and grammar totally different from English.
C
CAB or CABx: Citizens Advice Bureaux.
cerumen: another name for ear wax.
cilia: hairs towards the outside of the ear canal which move wax outwards out of the ear canal, part of the ear's cleaning mechanism.
Citizens Advice Bureaux: a network of advice agencies that provide free, confidential and independent advice, face–to–face and by telephone. They can provide help on things like debt, benefits, housing, legal, discrimination, employment, immigration, consumer and other problems.
cochlea: named after the Latin word for shell, the cochlea is a coiled, tapered tube inside the inner ear which transmits sound to the Organ of Corti, the sensory organ of hearing. It is a spiral tube about 3.5cm long that coils around. The spiral contains two fluid–filled chambers. The outer chamber starts at the oval window, goes to the end of the cochlea and then doubles back to the round window. Vibrations caused by sound pass from the stapes through the oval window and into the fluid in the outer chamber. The inner central chamber of the cochlea contains the Organ of Corti, which has thousands of small ‘hairs’ along the length of the cochlea. Each hair is connected to nerve fibres that join other similar fibres to form the auditory nerve which goes from the cochlea to the brain.
conductive hearing loss: a hearing loss that caused by a problem in the outer or middle ear and causes problems with the conduction of sound to the inner ear.
congenital: a condition that is recognised at birth, or that is believed to have been present since birth, including conditions which are inherited or caused by an environmental factor.
D
dBHL: ‘dB’ stands for decibels and HL stands for ‘hearing level’.
DdEF: Ddeaf Equality Forward
Ddeaf: Ddeaf Equality Forward uses the term ‘Ddeaf’ to refer to all Deaf, deaf, deafened, deaf blind and hard of hearing people.
deaf: with a small ‘d’, is a general term used to describe all deaf people (deafened, hard of hearing, partially deaf etc.). This group of deaf people tend not to identify themselves as part of the ‘Deaf community’, and use spoken language.
Deaf: with a capital D, is used to describe someone who is born or who became profoundly deaf at an early age and see themselves as part of the ‘Deaf community’. Their first or preferred language is usually sign language. Deaf people tend to see themselves as part of a linguistic minority, and not as disabled.
deafened: people born hearing who became deaf as adults, either suddenly after an injury or illness or over a long period, e.g. after exposure to loud noise.
Direct Payment: Direct Payments are cash payments made in lieu of social service provisions, to people who have been assessed as needing services. They can be made to disabled people aged 16 or over, to people with parental responsibility for disabled children, and to carers aged 16 or over in respect of carer services. The aim of a direct payment is to give more flexibility in how services are provided to people who are assessed eligible for social services support. By giving individuals money in lieu of social care services people have greater choice and control over their lives, and are able to make their own decisions about how their care is delivered.
Disability Living Allowance: a state benefit that is paid to people with a disability to help with the increased cost of daily living due to their disability. Your local Jobcentre or Benefits Agency office will be able to tell you if you may be eligible.
DLA: Disability Living Allowance.
DNA: Deoxyribonucleic acid. The molecules inside cells that carry genetic information and pass it from one generation to the next.
E
ear canal: the passage sound travels along from the outer ear to the middle ear
eardrum: the tympanic membrane, colloquially known as eardrum, is a thin membrane that separates the outer ear from the middle ear. Its function is to transmit sound from the air to the ossicles inside the middle ear. The malleus bone connects the eardrum to the other ossicles.
endolymph: fluid in the labyrinth, the organ of balance in the inner ear.
Eustachian tube: The middle ear is a sealed, air filled cavity allows the eardrum to move easily. The Eustachian tube connects the back of the nose to the middle ear. Air can pass from the back of the nose to the middle ear through the Eustachian tube to equalize the pressure between the outer and middle ear.
F
G
glue ear: another name for otitis media.
grommet: a small ventilation tube that is inserted temporarily into the eardrum in an operation called a myringotomy to treat the condition ‘glue ear’ (otitis media).
H
hammer: another name for the malleus.
hard of hearing: someone with a hearing loss but who has some useable hearing. They may use hearing aids, lip reading and other aids to communication. People who are hard of hearing may identify more with hearing people than the Deaf community. Their first language is likely to be spoken
I
incus: an anvil–shaped small bone or ossicle in the middle ear. It connects the malleus to the stapes.
inner ear: the part of the ear in the temporal bone consisting of the semicircular canal, vestibule and cochlea. It is contained within a system of spaces and canals, known as the osseous or bony labyrinth, in the temporal bone. These spaces and canals are divided into three sections: the vestibule, which contains two balance organs, the utricle and saccule; the semicircular canals, and the cochlea.
J
Jobcentre: Jobcentres offer a range of services for people with disabilities who want to find work. The Disability Employment Advisor at your local Jobcentre can advise you on training and support that may be available.
K
L
labyrinth: another name for the part of the inner ear that is part of the balance system, the vestibular apparatus. The labyrinth is a system of fluid passages in the inner ear, made up of the vestibular system and the auditory system.
M
malleus: a hammer–shaped small bone or ossicle (also known as the hammer) of the middle ear which connects with the incus and is attached to the inner surface of the eardrum
middle ear: between the outer and inner ear, the middle ear is separated from the ear canal by the eardrum. It contains the ossicles that transmit sound vibrations from the eardrum to the fluid in the inner ear. This causes wave in the fluid, which are transmitted as sound by the auditory nerve to the brain.
mild hearing loss: the quietest sounds people with mild deafness can hear is between 21 and 39 dBHL. They may have difficulty following speech in noisy situations.
mitochondria: structures in human cells that turn nutrients into energy for the cells.
mitochondrial DNA: DNA which is not located in the nucleus of the cell but in the mitochondria. Because mitochondrial DNA is inherited only from the mother, it provides an unaltered link to past generations.
moderate hearing loss: the quietest sounds people with moderate deafness can hear is between 40 and 69 dBHL. People with moderate deafness will have difficulty following speech without a hearing aid.
myringoplasty: an operation to treat a perforated eardrum where a tissue graft is used to patch the hole.
myringotomy: an operation to insert a tiny ventilation tube called a grommet temporarily into the eardrum to treat the condition ‘glue ear’ (otitis media).
N
neural hearing loss: hearing loss involving the auditory (8th cranial) nerve.
noise induced hearing loss: can happen when you have been exposed to loud noise over a long period of time, and is usually worst in the high frequencies. Speech sounds with the highest frequencies are consonant sounds such as "s", "sh", "t" and "p". The hearing loss will be similar in both ears and will get worse if you continue to be exposed to loud noise. The effect on hearing may not be noticed until years after you were exposed to the noise.
normal hearing: someone with thresholds between 0 and 20 dBHL across all frequencies of sound is said to have ‘normal’ hearing.
O
Organ of Corti: the part of the inner car that converts sound waves into nerve impulses that are then transmitted to the brain by the 8th cranial nerve – the auditory nerve.
ossicles: the three smallest bones in the human body. The ossicles consist of the malleus, incus, and stapes (known also as the hammer, anvil, and stirrup, found in the middle ear. They are part of the system that amplifies sound vibrations that enter the middle ear.
ossiculoplasty: an operation to repair or replace malformed or damaged ossicles.
otitis externa: a condition where the skin of the ear canal becomes inflamed, for example if you have scratched your ear or you have eczema. It may be painful and give you a watery discharge from your ears but it doesn't usually cause hearing loss. Ear drops from your doctor may help.
otitis media: an infection or inflammation of the middle ear caused by a viral or bacterial infection. This can cause the Eustachian tube to become blocked, preventing air from reaching the middle ear and the middle ear fills up with fluid that becomes thick, like glue, and is known as glue ear.
otosclerosis: a condition that often runs in families and often begins around the age of 30. It tends to affect more women than men. It is caused by a bony overgrowth of the stapes, one of the chain of ossicles in the middle ear. This link in the chain becomes more rigid and sound vibrations can't pass through it and hearing will gradually become worse. Hearing aids can be useful for people with otosclerosis unless hearing loss is severe. Often, an operation called a stapesectomy can be performed, where a tiny ‘peg’ replaces the stapes.
ototoxic drugs: drugs that can cause damage to hearing.
outer ear: made up of two parts, the pinna, the part you can see on the side of your head, and the ear canal – the passage sound travels along to the middle ear. The pinna helps to collect sounds and direct them along the ear canal. The canal is about 2.5cm or 1 inch long and lined with skin. Near to the outside the canal has hairs and glands that produce wax that keep it clean and help prevent infection. The hairs, called cilia move the wax outwards and that is why wax comes out of the ear.
oval window: a membrane–covered opening which leads from the middle ear to the vestibule of the inner ear. The end of the stapes fits into the oval window
P
partially deaf: similar to ‘hard of hearing’; people with a hearing loss but with some useful hearing, who tend to be part of the hearing community and culture
perforated eardrum: an eardrum with a hole or tear in it; can interfere with normal hearing and cause other ear problems. Perforated eardrums can be caused by untreated otitis media and other infections, head injuries, explosions, or poking things in your ear. Normally they heal naturally and any hearing loss is temporary. If the damage is more serious and operation called a myringoplasty can be performed, where a tissue graft is used to patch the hole.
permanent threshold shift: permanent hearing loss which can be due to exposure to loud noise, or acoustic trauma.
pinna: the visible part of the ear – the outer folds and the ear lobe; gathers sound waves in and enhances them as they move into the ear canal.
presbyacusis: a condition that is due to the loss of specialised cells that are needed for the cochlea to work properly, which occurs naturally with aging.
profound hearing loss: the quietest sounds profoundly deaf people can hear is 95 dBHL. BSL is often their first language, especially those born deaf or who lost their hearing at an early age. Severely or profoundly deaf adults, those who have lost their hearing later in life tend not to use BSL so much, and often rely on lip reading.
Q
R
RNID: Royal National Institute of the Deaf.
round window: membrane separating the middle ear and inner ear.
S
saccule: part of the vestibular apparatus that are part of the balance system.
semicircular canals: a system of fluid passages in the inner ear, comprising the vestibular system and the auditory system, which provides the sense of balance. It is named by analogy with the mythical maze that imprisoned the Minotaur, because of its appearance.
sensorineural hearing loss: hearing loss which is due to problems in the inner ear. This word though actually describes two types of hearing loss, sensory hearing loss, and neural hearing loss. Sensory hearing loss is due to problems in the cochlea, whereas neural hearing loss involves the auditory (8th cranial) nerve. It may be difficult to differentiate between sensory and neural hearing loss, but specialised hearing tests can pinpoint the difference. Sensorineural hearing loss is often the result of damage to the tiny hair cells in the cochlea. Unlike with disorders that affect the outer and middle ear, in which hearing loss is usually temporary and treated, sensorineural hearing loss due to damage to the hairs in the cochlea is permanent as the hair cells can't be replaced.
sensory hearing loss: hearing loss due to problems in the cochlea.
severe hearing loss: the quietest sounds people with severe deafness can hear is between 70 and 94 dBHL. They rely on lip reading a lot, even with a hearing aid. They often use British Sign Language (BSL) as their preferred way to communicate.
Sign Supported English: a form of English that additionally uses signs to convey meaning.
SSE: abbreviation for Sign Supported English.
stapes: (also known as the stirrup is the stirrup–shaped small bone or ossicle in the middle ear which attaches the incus to the oval window which is next to the vestibule of the inner ear. It is the smallest bone in the human body.
stapesectomy: an operation where a tiny ‘peg’ replaces the stapes which is often used to treat the condition otosclerosis.
stereocilia: tiny hair–like cells in the cochlea that convert the movement of fluid in the inner ear, which are sent along the vestibular nerve to the brain, where they are processed, giving your brain information about the position of your head.
stirrup: another name for the stapes bone in the middle ear.
T
temporary threshold shift: a temporary hearing loss which is usually a temporary dullness in hearing after exposure to loud noise. Hearing usually returns to normal within 48 hours, but this varies on the loudness of the noise, and how long you were exposed to it.
threshold: a hearing test finds the quietest sounds a person can hear – their thresholds – across a range of frequencies (pitches of sounds).
tinnitus: a medical term for any noise which people hear in one ear, both ears or in their head. These sounds do not come from outside the head, although they may occasionally sound as if they do. Apart from one or two rare conditions, tinnitus cannot be heard by anyone other than the person who has it. (From ‘Understanding tinnitus: managing the noises in your ears or in your head’, Keith Dunmore, Glynis Riddiford & Valerie Tait, RNID, 2003)
tympanic membrane: another name for the eardrum
U
utricle: part of the vestibular apparatus that are part of the balance system
V
vestibular apparatus: a system of fluid passages in the inner ear, made up of the vestibular system and the auditory system, which provides the sense of balance. The vestibular apparatus is made up of the saccule, utricle and semicircular canals, and plays an important role in balance. The saccule, utricle and semicircular canals aren't used for hearing.
vestibulocochlear/vestibular nerve: the eighth cranial nerve, also known as the auditory nerve. It is the nerve along which the hair cells of the inner ear transmit information to the brain. It is made up of the cochlear nerve, carrying information about hearing, and the vestibular nerve, carrying information about balance. The auditory nerve is also known as the acoustic nerve.
W
wax: ear wax is a yellowish, waxy substance secreted in the ear canal. It plays a vital role in the human ear canal in cleaning and lubrication, and also provides some protection from bacteria, fungus, and insects.
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