Glossary of Medical Terms

Acoustic Neurinoma - tumor, usually benign, whichmay develop on the hearing and balance nerves and can cause gradual hearingloss, tinnitus, and/or dizziness. (sometimes called vestibular schwannoma).Also see Neurofibromatosis Type 2.

Acquired Deafness - loss of hearing that occurs ordevelops some time during the lifespan but is not present at birth.

American Sign Language (ASL) - manual language withits own syntax and grammar, used primarily by people who are deaf.

Assistive Devices - technical tools and devices suchas alphabet boards, text telephones, or text-to-speech conversion software usedto aid individuals who have communication disorders perform actions, tasks, andactivities.

Audiologist - health care professional who istrained to evaluate hearing loss and related disorders, including balance(vestibular) disorders and tinnitus, and to rehabilitate individuals withhearing loss and related disorders. An audiologist uses a variety of tests andprocedures to assess hearing and balance function and to fit and dispensehearing aids and other assistive devices for hearing.

Audiometer - The electronic instrument used by theaudiologist for measuring the threshold of hearing

Audiometric Evaluation (AE) - term used to describea diagnostic hearing test, performed by a licensed audiologist. An AE is notjust pressing the button when you hear a "beep". Rather, anaudiometric evaluation allows the audiologist to determine the type and degreeof your hearing loss, and it tells the audiologist how well or how poorly youunderstand speech. The AE also includes a thorough case history (interview) aswell as visual inspection of the ear canals and eardrum.

Audiometry - Specific procedures by which thethreshold of hearing is measured

Auditory Brainstem Response (ABR) Test - Also calledBrainstem Evoked Response (BSER), Brainstem Auditory Evoked Response (BAER),and Auditory Evoked Response (AER), this test objectively measures hearing byplacing electrodes on the scalp to record the electrical activity in the brainwhen sound occurs. It is used for newborn babies, infants, and young childrenwho cannot respond reliably using standard procedures such as visual reinforcementaudiometry, play audiometry, or picture identification

Auditory Nerve - eighth cranial nerve that connectsthe inner ear to the brainstem and is responsible for hearing and balance.

Auditory Perception - ability to identify,interpret, and attach meaning to sound.

Auditory Prosthesis - device that substitutes orenhances the ability to hear.

Auditory Training Equipment - Supplementarylistening systems that increase audibility for the child with hearing loss. Theequipment can be a desktop system or an FM listening system.

Autoimmune Deafness - individual's immune systemproduces abnormal antibodies that react against the body's healthy tissues.

Balance - biological system thatenables individuals to know where their bodies are in the environment and tomaintain a desired position. Normal balance depends on information from thelabyrinth in the inner ear, from other senses such as sight and touch, and frommuscle movement.

Balance Disorder - disruption in the labyrinth, theinner ear organ that controls the balance system, which allows individuals toknow where their bodies are in the environment. The labyrinth works with othersystems in the body, such as the visual and skeletal systems, to maintainposture.

Barotrauma - injury to the middle ear caused by areduction of air pressure.

Basic training evaluation - A combination of testsand procedures used by audiologists to measure hearing ability

Benign Paroxysmal Positional Vertigo (BPPV) -balance disorder that results in sudden onset of dizziness, spinning, orvertigo when moving the head.

Bilateral hearing loss - hearing loss in both ears.

Binaural - Listening with both ears

Body Hearing Aid - A hearing aid in which themicrophone, amplifier, and battery are housed in a small unit worn on the body.An earmold is connected to a receiver that is connected by a cord to thehearing aid. This type of hearing aid is capable of providing powerfulamplification

Brainstem Implant - auditory prosthesis thatbypasses the cochlea and auditory nerve. This type of implant helps individualswho cannot benefit from a cochlear implant because the auditory nerves are notworking.

Captioning - text display of spokenwords, presented on a television or a movie screen, that allows a deaf orhard-of-hearing viewer to follow the dialogue and the action of a programsimultaneously.

Carrier - a person who has only one copy of arecessive disorder gene with a change in it. The person "carries" thechanged gene but shows no symptoms of the disorder. If both parents are carriers,each child has a 1 in 4 chance of inheriting two changed genes and showing thedisorder.

Central Auditory Processing Disorder - inability todifferentiate, recognize, or understand sounds; hearing and intelligence arenormal.

Cerumen - Earwax

Cholesteatoma - accumulation of dead cells in themiddle ear, caused by repeated middle ear infections.

Cochlea - snail-shaped structure in the inner earthat contains the organ of hearing.

Cochlear Implant - medical device that bypassesdamaged structures in the inner ear and directly stimulates the auditory nerve,allowing some deaf individuals to learn to hear and interpret sounds andspeech.

Conductive Hearing Impairment - hearing loss causedby dysfunction of the outer or middle ear.

Cued speech - A system of hand shapesused to supplement the information received from speech reading (lip-reading).

DEAF - Webster's New World Dictionary CollegeEdition defines deaf as totally or partially unable to hear. It generallyrefers to people who usually have little or no useful residual hearing and whoemploy sign language as their primary mode of communication. Deaf people mayalso use speech reading, hearing aids, and other assistive technology to aidcommunication. People who are deaf can be categorized into two groups:congenitally deaf (those who were born deaf) and adventitiously deaf (those whowere born with hearing but whose sense of hearing became nonfunctional later inlife).

Decibel(db) - unit that measures the intensity orloudness of sound.

Dispensing Audiologist - An audiologist who, inaddition to evaluating a persons hearing ability, selects and fits hearingaids; orders the instruments; sells them to the patients; and providesfollow-up care

Dysequilibrium - any disturbance of balance.

Ear Infection - presence and growth ofbacteria or viruses in the ear.

Earmold - A specially molded piece of lucite orvinyl material that is attached to a hearing aid to conduct sound into the ear.

Ear Wax - yellow secretion from glands in the outerear (cerumen) that keeps the skin of the ear dry and protected from infection.

Endolymph - fluid in the labyrinth (the organ ofbalance located in the inner ear that consists of three semicircular canals andthe vestibule).

Enlarged vestibular aqueducts (EVA) - vestibular aqueductsare narrow, bony canals that travel from the inner ear to inside the skull. Avestibular aqueduct is often considered enlarged if it is greater than 1.5millimeters in size. Research suggests that most children with EVA will developsome degree of hearing loss.

ENT Clinic - Anabbreviation for ear, nose, and throat clinic, a place where hearing loss andproblems of the ear are diagnosed and treated

Eustachian Tubes - The soft tubes connecting themiddle ear and the back of the mouth that serve to equalize air pressure and todrain fluids.

Feedback - A term that describes what occurs whentoo much amplified sound escapes from the ear and is picked up by themicrophone of the hearing aid causing a high-pitched whistling sound. Thewhistling persists until turning down the gain control reduces theamplification of the hearing aid.

Frequency - The number of sound vibrations persecond. Expressed in Hertz (Hz), corresponding to the pitch of sound

Cells - sensory cells of the inner ear, which areped with hair-like structures, the stereocilia, and which transform themechanical energy of sound waves into nerve impulses.

Hard of Hearing - The term used to describe a degreeof hearing loss ranging from mild to profound for which a person usuallyreceives some benefit from amplification. Most people who are hard of hearingare oralists (communicate by using their voice), although a small number learnsign language. Usually they participate in society by using their residualhearing with hearing aids, speech reading, and assistive devices to facilitatecommunication

Hearing - series of events in which sound waves inthe air are converted to electrical signals, which are sent as nerve impulsesto the brain, where they are interpreted.

Hearing Aid - electronic device that bringsamplified sound to the ear. A hearing aid usually consists of a microphone,amplifier, and receiver.

Hearing Disorder - disruption in the normal hearingprocess that may occur in outer, middle, or inner ear, whereby sound waves arenot converted to electrical signals and nerve impulses are not transmitted tothe brain to be interpreted.

Hereditary Hearing Impairment - hearing loss passeddown through generations of a family.

Inner Ear - part of the ear thatcontains both the organ of hearing (the cochlea) and the organ of balance (thelabyrinth).

Labyrinth- organ of balance located in the inner ear. The labyrinth consists of threesemicircular canals and the vestibule.

Labyrinthine Hydrops - excessive fluid in the organof balance (labyrinth); can cause pressure or fullness in the ears, hearingloss, dizziness, and loss of balance.

Labyrinthitis - viral or bacterial infection orinflammation of the inner ear that can cause dizziness, loss of balance, andtemporary hearing loss.

Lip reading - The ability to gainunderstanding of what is being said by watching the lips as well as by watchingthe face, expressions, and gestures. The term speech reading is now recognizedas more descriptive because it includes watching the facial expressions, gestures,and body language as well as the lips.

Mastoid - back portion of the temporal bone thatcontains the inner ear.

Mastoid Surgery - surgical procedure to removeinfection from the mastoid bone.

Medical Clearance - A required recommendationstating a physicians approval for the purchase of hearing aids, implying thatthere are no medical contraindications for hearing aid use

Mnire's Disease - inner ear disorder that canaffect both hearing and balance. It can cause episodes of vertigo, hearingloss, tinnitus, and the sensation of fullness in the ear.

Meningitis - inflammation of the meninges, themembranes that envelop the brain and the spinal cord; may cause hearing loss ordeafness.

Middle Ear - part of the ear that includes theeardrum and three tiny bones of the middle ear, ending at the round window thatleads to the inner ear.

Motion Sickness - dizziness, sweating, nausea,vomiting, and generalized discomfort experienced when an individual is inmotion.

Neural Prostheses - devices that substitute for aninjured or diseased part of the nervous system, such as the cochlear implant.

Neurofibromatosis Type 1 (NF-1 von Recklinghausen's)- group of inherited disorders in which noncancerous tumors grow on severalnerves that may include the hearing nerve. The symptoms of NF-1 includecoffee-colored spots on the skin, enlargement, deformation of bones, andneurofibromas.

Neurofibromatosis Type 2 (NF-2) - group of inheriteddisorders in which noncancerous tumors grow on several nerves that usuallyinclude the hearing nerve. The symptoms of NF-2 include tumors on the hearingnerve which can affect hearing and balance. NF-2 may occur in the teenage yearswith hearing loss. Also see acoustic neurinoma.

Neurogenic Communication Disorder - inability toexchange information with others because of hearing, speech, and/or languageproblems caused by impairment of the nervous system (brain or nerves).

Noise-Induced Hearing Loss - hearing loss caused byexposure to harmful sounds, either very loud impulse sound(s) or repeatedexposure to sounds over 90-decibel level over an extended period of time thatdamage the sensitive structures of the inner ear.

Nonsyndromic Hereditary Hearing Impairment - hearingloss or deafness that is inherited and is not associated with other inheritedclinical characteristics.

Otitis Externa - inflammation of the outer part ofthe ear extending to the auditory canal.

Otitis Media - inflammation of the middle ear causedby infection.

Otoacoustic Emissions - low-intensity soundsproduced by the inner ear that can be quickly measured with a sensitivemicrophone placed in the ear canal.

Otolaryngologist - physician/surgeon who specializesin diseases of the ears, nose, throat, and head and neck.

Otologist - physician/surgeon who specializes indiseases of the ear.

Otosclerosis - abnormal growth of bone of the innerear. This bone prevents structures within the ear from working properly andcauses hearing loss. For some people with otosclerosis, the hearing loss maybecome severe.

Ototoxic Drugs - drugs such as a special class ofantibiotics, aminoglycoside antibiotics, that can damage the hearing andbalance organs located in the inner ear for some individuals.

Outer Ear - external portion of the ear, consistingof the pinna, or auricle, and the ear canal.

Perception (Hearing) - process ofknowing or being aware of information through the ear.

Perilymph Fistula - leakage of inner ear fluid tothe middle ear that occurs without apparent cause or that is associated withhead trauma, physical exertion, or barotrauma.

Postauricular - An expression used to describehearing aids worn behind the ear

Postlingually Deafened - individual who becomes deafafter having acquired language.

Prelingually Deafened - individual who is eitherborn deaf or who lost his or her hearing early in childhood, before acquiringlanguage.

Presbycusis - loss of hearing that gradually occursbecause of changes in the inner or middle ear in individuals as they growolder.

Pure tone - A soundoccurring at one frequency used in audiometry.

Pure tone average - An average of hearing thresholdsfor selected frequencies, usually 500 Hz, 1000 Hz, and 2000 Hz used to expressthe degree of hearing loss

Relay service - Enables text telephone (TTY) usersto communicate with non-TTY users by way of a relay service communicationsoperator. The ADA mandated a nationwide relay service to be completed in 1993

Round Window - membrane separating the middle earand inner ear.

Semicircular Canals - The organ ofbalance connected directly to the cochlea in the ear

Sensorineural Hearing Loss - hearing loss caused bydamage to the sensory cells and/or nerve fibers of the inner ear.

Sign Language - method of communication for peoplewho are deaf or hard of hearing in which hand movements, gestures, and facialexpressions convey grammatical structure and meaning.

Speech audiometry - Testing hearing by using speech,usually lists of isolated words or sentences

Sudden Deafness - loss of hearing that occursquickly due to such causes as explosion, a viral infection, or the use of somedrugs.

Syndromic Hearing Impairment - hearing loss ordeafness that, along with other characteristics, is inherited or passed downthrough generations of a family.

Temporary Threshold Shift (TTS) - A loss of hearingassociated with the effect of loud noise, which disappears after a period ofrecovery.

Threshold of Hearing - The faintest sound that canbe consistently heard at each of the tested frequencies in an audiometricevaluation.

Tinnitus - sensation of a ringing, roaring, or buzzingsound in the ears or head. It is often associated with many forms of hearingimpairment and noise exposure.

Tympanic membrane - Another name for the eardrum

Tympanogram - The graph that results fromtympanometry, describing the acoustic evaluation of the outer and middle ear'sability to accept and conduct sound.

Tympanometry - The measurement of the outer andmiddle ear's ability to accept and conduct sound.

Tympanoplasty - surgical repair of the eardrum(tympanic membrane) or bones of the middle ear.

Usher Syndrome - hereditary diseasethat affects hearing and vision and sometimes balance.

Vertigo - illusion of movement; a sensation as ifthe external world were revolving around an individual (objective vertigo) oras if the individual were revolving in space (subjective vertigo).

Vestibular System - system in the body that isresponsible for maintaining balance, posture, and the body's orientation inspace. This system also regulates locomotion and other movements and keepsobjects in visual focus as the body moves.

Vestibule - bony cavity of the inner ear.

Vibrotactile Aids - mechanical instruments that helpindividuals who are deaf to detect and interpret sound through the sense oftouch.

Visual Reinforcement Audiometry (VRA)- A lighted or animated toy is used to reward a correct response when testingthe hearing of very young children (about two years and younger). When the toyis used to get the child to turn toward the source of the sound, it is calledConditioned Orientation Response (COR). The results of the child's responsescan be plotted on an audiogram in the same manner as when adults raise theirhand, use the signal button, or say yes.

Waardenburg Syndrome - hereditary disorder that ischaracterized by hearing impairment, a white shock of hair and/or distinctiveblue color to one or both eyes, and wide-set inner corners of the eyes. Balanceproblems are also associated with some types of Waardenburg syndrome.

Last Updated: 5/12/11