Glossary For Parents This is not a complete or comprehensive glossary of audiologic and medical terms. It does include many technical and often unfamiliar terms that parents may hear used in connection with their child s hearing-or hearing loss. If you happen to come across any other terms that are not clear, ask your otologist or audiologist for a full explanation of what is meant. Or ask us for an explanation. Acoustic Reflex: reflex caused by a muscle attached to the eardrum which occurs when a loud sound is heard. This reflex can be measured by an audiologist to aid in diagnosing hearing loss Atresia: closure of the ear canal or absence of an ear opening. Audiogram: A graph on which is recorded the child s responses to various sounds. The numbers across the top show pitch from low (on the left) to high (on the right). The numbers from the top to bottom of the audiogram show the level of loudness. For additional information, please see our paper on hearing tests, which accompanies Lesson Two. Audiologic Evaluation: tests conducted by an audiologist to determine whether a hearing loss is present, what tones (pitches) are affected, the degree of hearing loss, and the type of hearing loss. The evaluation also includes recommendations for medical follow-up and/or the selection of appropriate hearing aids. Audiologist: a health care professional specializing in the measurement of hearing and the correction of hearing impairments or hearing loss. Acoustic Brainstem Response Test (ABR): the objective measurement of the brain s response to sound. The brain emits an electric signal, which is picked up by small electrodes placed on the child s head. Children more than three months of age need to be sedated for this test, since movement and vocalizing can impair the test results. Air Conduction: Testing: testing through speakers, earphones or insert earphones. Air Bone Gap: (see Mixed Hearing Loss) Auditory Neuropathy: inability of the auditory nerve to transmit sound clearly to the brain. Analog Hearing Aid: circuitry modifies and amplifies the incoming signal. Auditory Nerve: the nerve which carries sound from the cochlea to the brain.
Glossary For Parents Behavioural Observation Audiometry: Observation of a baby s responses to sound in a test booth. This is generally seen by changes in facial expression, specifically eyebrow furrowing, eye widening or searching. Binaural amplification: two separate and complete hearing aids, one for each ear. Bone Conduction: measurement made with a bone conduction vibrator of an audiometer which indicates the hearing sensitivity of the inner ear and auditory nerve. It passes the middle ear which can be affected by infection and fluid, and the outer ear which can be occluded with wax. Cerumen (Earwax): an oily glandular substance that lubricates the ear; sometimes it hardens and can block the ear canal. It should be removed only by an otologist. Cochlea: the snail-like organ of hearing located in the inner ear. Cochlear Implant: a device designed to allow a deaf person to perceive sound. The implant is composed of two parts: a surgically implanted electrode array and an externally worn speech processor. Compression: a method of controlling amplification in the hearing aid so a child is not made uncomfortable by very loud sounds. The sound is not amplified by the same decibel amount as the input signal (e.g. input signal is 20 db and the hearing aid amplifies it 15 db). Conductive Hearing Loss: caused by pathology of the outer or middle ear. Congenital Deafness: present at birth. Decibel: (see Intensity) Degree Of Hearing Loss: Normal...0-15 db Slight...15-25 db Mild...25-40 db Moderate...40-55 db Moderately-severe...55-70 db Severe...70-90 db Profound...90 + db Digital Hearing Aids: the input signal is converted as sets of digits (as is done by computers) then modified and amplified. Digitally Programmable Hearing Aids: an analog hearing aid which is programmed by a computer or hand held system which programs it in a digital manner. Distortion: 1) the hearing aid does not reproduce sound clearly. When this occurs, the aid must be taken to the hearing aid professional for repair. 2) the child is unable to perceive sound clearly even with appropriate amplification. The Ear: Outer Ear: the auricle or pinna (the part of the ear on the outside of the head) and the ear canal. The outer ear ends at the eardrum. Middle Ear: located between the outer ear and inner ear, separated from the ear canal by the eardrum. The middle ear contains three tiny bones (the ossicles). These pump sound vibrations from the eardrum to the fluid of the inner ear. Inner Ear: the innermost part of the ear. It is composed of the hearing organ (the cochlea), the balance mechanism (the semi-circular
Glossary For Parents FM System: an amplification device consisting of two parts. 1) a microphone worn by the teacher and 2) a special hearing aid which will pick up the signal from that microphone. The voice then appears to be very close to the child s ear even when the child is standing a considerable distance away. This is very helpful when there is background noise. canal), and the auditory nerve. Vibration pumped into the fluid by the little bones in the middle ear causes waves in the fluid, which are transmitted as sound by the auditory nerve to the brain. Eardrum: The tympanic membrane which separates the outer ear from the middle ear. Earmould: an individually fitted plastic mould with a channel to carry sound from the hearing aid into the ear. Usually fitted by the hearing aid professional and made by a laboratory or manufacturing firm. Worn in the opening of the outer ear. Expressive Language: the language your child uses to express himself. External Otitis: inflammation of the outer ear. Should be treated by an otologist, ENT (ear, nose and throat) specialist, or a pediatrician. Feedback: the shrill whistling sound made when the hearing aid microphone is covered or the earmould does not fit properly or is damaged. Frequency (Pitch or Tones): the measurement of sound in Hertz (Hz). Most speech sounds fall within the speech range of 250 (low pitch) to 4000 (high pitch) Hz. Gain: the decibel amount of amplification in a hearing aid. If a hearing aid amplifies sound by 50 db, there is 50 db of gain. Hair Cells: small cells located in the cochlea (sense organ for sound) which stimulate the auditory nerve to carry sound to the brain. Hearing Aid: an electronic device for hearingimpaired persons that amplifies sound and takes it directly to the ear. Hearing Aid Professional: sells and services hearing aids after helping select and fit them according to the audiologist s specifications. Hearing Aid Evaluation: selection of an appropriate hearing aid by the audiologist. Hertz: (see Frequency) Insert Earphones: soft sponge material that is inserted into the ear canal. They are often used instead of earphones which cover the entire outer ear. Intensity (Loudness): a measurement of sound in decibels (db). Based on this measurement, it is determined whether the hearing loss is mild, moderate, severe or profound in degree.
Glossary For Parents Language: what you say. Language can be spoken, written or signed. Monaural: one hearing aid, fitted only to one ear. Language Or Speech Therapist (or Clinician): a highly trained professional who works with children (or adults) who have language or speech problems. This may include children whose language and speech problems result from impaired hearing. Multiple Memory Hearing Aids: hearing aids that are programmed for different listening situations, such as a quiet classroom or a noisy play environment. Mainstreaming: placing a hearing-impaired child into a classroom with normal hearing children. Myringotomy: surgery which opens the eardrum to remove fluid from the middle ear. This is commonly described as having tubes put in the ears. Nerve Deafness: see sensorineural hearing loss. Ossicles: three tiny bones in the middle ear. Manual Communication: use of sign language, cued speech or finger spelling. Otitis/Otitis Media: inflammation of the middle ear. Often this is accompanied by fluid, and must always be treated by a medical doctor. Children may be uncomfortable and need to remove their hearing aids while they have this medical condition. Otoacoustic Emissions (OAE): the emission of sound from the cochlea which is measured in the ear canal. Maximum Power Output (MPO): the cut off point above which a hearing aid will no longer amplify sound. Mixed Hearing Loss: a hearing loss that is partly sensorineural and partly conductive. A child with a sensorineural loss, for example, could also have a conductive loss from fluid in the ear caused by a middle ear infection. The result would be a mixed hearing loss. Otolaryngologist: a medical doctor specializing in problems of the ear, nose and throat. Sometimes referred to as an ENT doctor. Otologist: a medical doctor specializing in problems of the ear, including but not limited to deafness.
Glossary For Parents PE Tube: (pressure equalization or myringotomy tube) a very small tube placed in the ear drum to permit fluid to drain and air pressure to remain constant in the middle ear. Play Audiometry: the audiologist teaches the child to respond with some action whenever he hears a sound. He may learn, for example, to put a peg in a hole, a ring on a peg, or a piece in a puzzle every time he hears a sound. Sensorineural Hearing Loss: term used in the past when it was not possible to determine if a hearing loss which was in the auditory nerve or cochlea. Hearing losses are now defined as cochlear or neural. Speech: how we pronounce words. Stenosis: partial closure or narrowing of the ear canal. Threshold: the softest sound a person can hear. Total Communication: use of manual communication with spoken language (sign and spoken language). Post-lingual Deafness: hearing loss occurring after the child has learned to talk. Tympanometry (Impedance Audiometry): testing to measure the ability of the middle ear to conduct sound to the inner ear. Pre-lingual Deafness: hearing loss occurring before the child has learned to talk. Programmable (Multichannel) Hearing Aids: each frequency (tone) is programmed separately to provide the correct amount of gain for the hearing loss. Real Ear Measurement (Probe Microphone Measurement): measurement of the child s ear canal while wearing amplification to determine the exact level of sound which reaches the ear. Receptive Language: the language your child understands. Residual Hearing: a child s ability to hear without amplification. Sound Field Testing: testing in a soundproof booth using speakers instead of earphones. This is done for very small children who will not accept earphones and while children are wearing hearing aids. Types Of Hearing Aids: In-The-Ear and In-The-Canal He a r i n g A id s: very small aid worn completely in the ear. Suitable for mild to severe hearing losses. Rarely recommended for children. Behind-the-ear Hearing Aids: a small hearing aid worn behind the ear, connected to the ear opening by an earmould.
Glossary For Parents Bone-conduction Hearing Aids: a headband with a vibrator worn against the bony structure of the skull behind the ear. Vibrations of sound waves are carried through the bone, bypassing the outer and middle ear. Suitable for children with conductive hearing loss from atresia or stenosis. Unilateral Hearing Loss: hearing loss only in one ear. Vestibular System: balance organ located next to the cochlea. Visual Reinforcement Audiometry (VRA): the audiologist teaches the child to look toward a toy which lights up or moves each time the child hears a sound. Body-level Hearing Aids: the main part of the hearing aid is similar to a small box or case, which holds the microphone and amplifier, and is attached to the earmould by a thin cord. The Elizabeth Foundation Southwick Hill Road Cosham Hampshire PO6 3LL Tel: 023 9237 2735 Fax: 023 9232 6155 www.elizabeth-foundation.org Email: info@elizabeth-foundation.org Registered Charity No. 293835