Glossary

The reflex caused by the involuntary contraction of 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 identifying deafness.

This is the difference (or gap) between the two lines showing air-conduction and bone-conduction hearing test results plotted on an audiogram. An air-bone gap – i.e. a difference between the air-conduction and bone- conduction test results – indicates problems somewhere in your outer and/or middle ears (see ‘Mixed deafness’).

The reflex caused by the involuntary contraction of 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 identifying deafness.

A graph which records a child’s responses to various sounds measured through hearing tests or audiological evaluations. The numbers across the top show pitch or frequency 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. The top numbers show the softer sounds and the bottom the louder sounds.

The closure of the ear canal or absence of an ear opening.

A specialist dealing with the identification, medical treatment, habituation and rehabilitation of children and adults with disorders of hearing and balance.

Tests conducted by an audiologist to determine whether deafness is present, what tones (pitches) are affected, the degree of deafness, and the type of deafness. The evaluation may also include recommendations for medical follow-up, further investigations ie scanning and/or the selection of appropriate hearing aids.

A health care professional specialising in the measurement of hearing and the treatment of deafness.

The objective measurement of the brain’s response to sound. The test equipment features small electrodes placed that are on the child’s head to pick up electric signals emitted by the grain. Movement and vocalising can impair the quality and ability to reproduce test results so is ideally performed when the child is asleep. Occasionally a child is sedated or may be anaesthetised for this test.

The nerve which carries sound from the cochlea (see below) to the brain.

This hearing condition occurs when sound reaches the inner ear, and the inner ear can detect the sound, but the auditory nerve is not able to send this signal to the brain. In medical terms it is considered to be an asynchrony (mismatch) between the function of the cochlea and the brainstem.

Observation of a baby’s responses to sound which is often monitored from the time aids are fitted. This is generally seen by changes in facial expression, specifically eyebrow furrowing, eye widening or stilling to sound. This is the first type of measurement of aided benefit and tends to occur before a child is developmentally ready for more formal testing.

A hearing aid worn behind the ear, of varying sizes dependent upon degree of deafness, connected to the ear opening by an ear mould.

Two ears (both ears).

Two separate and complete hearing aids, one for each ear.

Similar to other hearing aids, but instead of being inserted into the ear canal or held behind the ear, it is fixed to an implant in the skull. This implant is inserted in an operation under general anaesthetic. A BAHA works by conducting sound through the skull bone to the inner ear.

Measurement made with a bone conduction vibrator, which sits behind the ear, and which indicates the hearing function of the inner ear and auditory nerve. It bypasses the middle ear which can be affected by infection and fluid, and the outer ear (in particular the ear canal) which can be blocked or partially-blocked with wax. During neo-natal testing this will often be held in place by the tester but will be worn on a head band for toddlers and older children.

The cochlea is the organ of hearing, shaped like the shell of a snail, located in the inner ear.

A type of hearing technology which is used often for patients who are profoundly deaf where standard hearing aids are not considered sufficient to enable a patient to access normal language. The implant is composed of two parts: a surgically implanted electrode array and an externally worn speech processor.

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). This also can be frequency specific which enables greater access to the quieter speech sounds.

Deafness that is caused by a problem in the outer or middle ear typically glue ear or middle ear effusion. This can be temporary or permanent.

Deafness that is present at birth.

The measure used for the loudness or intensity of sound (see Intensity).

The degree of deafness someone has is classed as mild, moderate, severe or profound depending on the quietest sound they are able to hear:

Normal hearing levels: able to hear sounds up to 20dB
Mild deafness: able to hear sounds in 21-40dB range
Moderate deafness: able to hear sounds in 41–70dB range
Severe deafness: able to hear sounds in 71-95dB range
Profound deafness: able to hear sounds above 95dB

This type of hearing aid converts sound waves (the input signal) into sets of digits that microprocessors in the hearing aid can then electronically modify and amplify. Modern digital hearing aids tend to output a better quality amplified sound than older analogue/non-digital hearing aids.

This term can have 2 meanings:
1. A hearing aid does not reproduce sound clearly – when this occurs, you need to take it to your hearing aid professional for repair.
2. The child is unable to perceive sound clearly even with appropriate amplification.

The ear is divided into three parts: the outer ear, the middle ear and the inner ear. For full details about the parts of the ear and a diagram see our ‘Technology and terminology’ course

The eardrum is the tympanic membrane which separates the outer ear from the middle ear.

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. It is worn in the opening of the outer ear. As children grow they need ear moulds being replaced regularly. There are many different types of earmould, earmould materials, colours etc which will be available and can be discussed with your audiologist.

An oily glandular substance that lubricates the ear canal – the medical term for earwax is cerumen. Sometimes it hardens and can block the ear canal. It should be removed only by a (specialist) nurse or ENT specialist.

The words and sentences (or signs) a child uses to express him/herself.

The shrill whistling sound made when the hearing aid microphone is covered or the earmould does not fit properly or is damaged. Feedback can also be caused by blocked tubing and excessive wax in the ear canal in front of the ear drum.

An amplification device consisting of two parts:
1. A microphone (transmitter) worn by the teacher, and
2. A receiver worn by the child which will pick up the signal from the transmitter. 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. There are a variety of different FM systems (sometimes called radio aid devices) available which are worn in different ways. Newer technology now allows for the receiver to be built in as a part of the hearing aid and this is known as an integrated FM system.

The measurement of sound in Hertz (Hz). Most speech sounds fall within the speech range of 500Hz (low pitch) to 6000Hz (high pitch).

The decibel amount of amplification in a hearing aid. If a hearing aid amplifies sound by 50 dB, there is 50 dB of gain.

A build-up of fluid in the middle ear that may lead to conductive deafness.

Small ventilation tubes that an ENT specialist may inserted into the eardrum under anaesthetic to drain middle ear fluid from the middle ear out of the ear (see Myringotomy).

Small cells located in the cochlea (sensory organ for sound) which stimulate the auditory nerve to carry sound to the brain.

Your child’s hearing age begins on the date they were fitted with their first hearing aids or, if they are profoundly deaf, when their cochlear implants are activated and appropriately tuned.

An electronic device that amplifies sound and takes it directly to the ear. Types of hearing aid include: behind the ear, bone anchored, in the ear and in the canal, and cochlear implants.

Measurement of the benefit offered by a hearing aid(s). This may involve measurement of hearing level with hearing aids worn and compared to hearing levels without in the same test. For younger children this may involve identification of the ling sounds or some speech identification tests carried out both with and without visual clues.

The most common types of hearing tests (or audiological evaluations) are: air conduction audiometry, audiological brainstem response, behavioural observation testing, oto-acoustic emissions testing, real ear measurement, sound field testing and visual reinforcement audiomentry.

The innermost part of the ear. It is composed of the hearing organ (the cochlea), the balance mechanism (the semi-circular canals), 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 by the auditory nerve to the brain.

Soft sponge material that is inserted into the ear canal. They are often used instead of headphones which cover the entire outer ear.

A measurement of sound in decibels (dB). Based on this measurement, the degree of deafness is classed as mild, moderate, severe or profound in degree.

A very small hearing aid worn completely in the ear. Rarely recommended for children and not available on NHS.

The method by which you communicate. Language can be spoken, written or signed. It is often divided into receptive language (what is understood) and expressive language (what is said).

Placing a deaf child (often with a learning support assistant) into a classroom alongside children with normal hearing.

Use of sign language, cued speech or finger spelling.

The cut-off point above which a hearing aid will no longer amplify sound. This protects the ear from sounds that are too loud.

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.

Deafness that is partly sensorineural and partly conductive. A child with sensorineural deafness, for example, could also have conductive deafness from fluid in the ear caused by a middle ear infection. The result would be mixed deafness.

One hearing aid, fitted only to one ear (mono = one, aural = ear).

Surgery which opens the eardrum to remove fluid from the middle ear. This occurs prior to the fitting of grommets.

see Sensorineural deafness.

Three tiny bones in the middle ear – called the malleus (hammer), incus (anvil) and stapes (stirrup) after their shapes.

Inflammation of the outer ear. This may require treatment by a GP, ENT (ear, nose and throat) specialist, or a Paediatrician.

Inflammation of the middle ear which may sometimes also be associated with glue ear. It is always recommended to suspend the use of a hearing aid in the affected ear until the inflammation has fully cleared.

The measurement of activity of the outer hair cells of the cochlea which is measured by a probe placed in the ear canal.

A medical professional more commonly known as an ENT Consultant.

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.

The nature of disease and its causes, processes, development and consequences.

A hearing test in which the audiologist conditions/trains the child to respond with some action whenever a sound is heard. Common examples are to put a peg in a hole, a ring on a peg, or a model character in a boat.

Deafness occurring after the child has learned to talk.

Deafness occurring before the child has learned to talk.

A person/organsation who sells and services hearing aids at a cost. Not part of the NHS (which is free at the point of delivery).

A type of measurement used to verify the true performance of a hearing aid when it is in the ear. Due to the nature and duration of this measurement it is often not carried out in children. As an alternative, a method called Real Ear Coupler Differences or RECD will be used which uses both a very quick measurement in the ear and measurements in a 2cc coupler within a computer test system to represent the function and size of a child’s ear.

The words and sentences (or signs) your child understands.

A child’s level of hearing without using amplification (hearing aids).

Permanent sensorineural deafness is most likely the result of damage to the hair cells within the cochlea or the hearing nerve (or both). This may also be described as cochlear, neural or inner ear deafness.

Testing using loudspeakers instead of earphones. This is done for very small children who will not accept earphones and while children are wearing hearing aids.

How we pronounce the sounds which make up words. It is also sometimes referred to as “phonology” or “articulation” or “speech sounds”.

A highly trained professional who works with children (or adults) who have language and/or speech problems. Some speech and language therapists have specific experience supporting children whose language and speech problems result from deafness.

Partial or full closure or narrowing of the ear canal.

The softest/quietest sound a person can hear.

This is a way of communicating with people with communication difficulties and combines lots of different ways of communicating. It is not just about speech. A total communication (TC) approach aims to give each child access to the type of communication that is appropriate for them (may be different for each child). For deaf children it is often used to describe a combination of spoken language and sign language.

Testing to measure the ability of the middle ear to conduct sound to the inner ear.

Deafness only in one ear.

The balance organ located next to the cochlea.

The audiologist conditions/trains the child with a visual reward, often a moving or flashing toy when a sound is heard. The test can be done through speakers, both with and without hearing aids, or with headphones or inserts.