Glossary of terms

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 diagnosing 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 Hearing Loss).

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 diagnosing 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 diagnosis, 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.

Considered to be an asynchrony (mismatch) between the function of the cochlea and the brainstem. [Auditory neuropathy is a hearing disorder in which sound enters the inner ear normally but the transmission of signals from the inner ear to the brain is impaired. http://www.nidcd.nih.gov/]

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 occluded 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.

Cochlea: organ of hearing, shaped like the shell of a snail, located in the inner ear.

A type of hearing aid which is used often for patients with a profound loss 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.