Glossary

The Joint Committee on Infant Hearing timeline: screen by 1 month, confirm diagnosis by 3 months, and enrol in early intervention by 6 months. The 2019 statement adds an aspirational 1-2-3 target.

Middle-ear immittance testing using a 1000 Hz probe tone, used in infants under about six months because the standard 226 Hz probe is unreliable in the highly compliant immature ear canal.

A transient auditory evoked potential. The frequency-specific (tone-burst) threshold ABR, with bone-conduction, is the cornerstone objective estimate of hearing level in infants; results are reported in estimated hearing level (eHL).

A pattern of present cochlear function (OAEs and/or cochlear microphonic) with an absent or grossly abnormal ABR, indicating disordered neural transmission. Speech perception is often disproportionately poor.

An objective, frequency-specific threshold estimate from modulated tones, detected statistically rather than by reading a waveform. Complements the ABR and can present at very high intensities.

An automated screening test that presents clicks and algorithmically detects a brainstem response, testing the pathway through the auditory nerve and lower brainstem — so it flags neural lesions that OAEs miss.

Observing changes in an infant's behaviour (stilling, eye-widening, startle) in response to sound. Crude, non-ear-specific and prone to bias; a gross cross-check, not a quantitative test.

Eligibility for a cochlear implant, judged from the audiogram together with demonstrably limited aided benefit after a hearing-aid trial, plus aetiological and imaging work-up. Earlier implantation predicts better outcomes.

An implanted device that bypasses damaged hair cells to stimulate the auditory nerve directly. Considered for severe-to-profound bilateral SNHL with insufficient benefit from hearing aids; outcomes are strongly age-dependent.

A receptor potential from cochlear hair cells that follows the stimulus waveform and reverses with stimulus polarity. Its presence alongside an absent ABR is a hallmark of auditory neuropathy.

Absence or hypoplasia of the cochlear (auditory) nerve, shown on MRI. It limits or contraindicates cochlear implantation and is a key reason imaging is mandatory in the work-up.

From about 2.5 to 5 years, the listening response is turned into a game (e.g. drop a peg when the tone is heard), sustaining cooperation long enough to obtain ear- and frequency-specific thresholds.

The leading non-genetic cause of childhood sensorineural hearing loss and a frequent cause of late-onset, progressive loss — a key reason for surveillance after a passed newborn screen.

The governing rule of paediatric audiology: no single test result is accepted until confirmed by an independent measure. Conflicting results are often diagnostic rather than noise.

The unit in which tone-burst ABR thresholds are reported, derived by applying age-appropriate correction factors to the recorded ABR threshold so it approximates the behavioural audiogram.

Foam-tip earphones that deliver sound to each ear separately, allowing ear-specific thresholds in behavioural and objective testing and reducing cross-hearing.

The body whose position statements set the principles of early hearing detection and intervention, including the 1-3-6 benchmarks and the risk-indicator register for ongoing surveillance.

The softest level that reliably produces a behavioural response. In young children this is a ceiling on the true threshold, not the threshold itself — hence the cross-check against objective measures.

Low-level sounds generated by healthy cochlear outer hair cells in response to stimulation. Fast and frequency-specific, but normal in auditory neuropathy because they test only as far as the cochlea.

A list of indicators (e.g. congenital CMV, family history, NICU care, craniofacial anomalies, meningitis) that mandate audiological surveillance beyond the newborn screen, because some losses are late-onset or progressive.

Presenting stimuli through loudspeakers rather than earphones. Convenient for young infants but reflects only the better-hearing ear, so it cannot establish ear-specific thresholds.

Screening of every newborn's hearing — not only those with risk factors — because targeted screening alone misses about half of affected infants. Delivered with OAE and/or AABR.

The behavioural test of choice from about 6 months to 2.5 years: a conditioned head-turn toward a sound is rewarded by a visual reinforcer, allowing minimum response levels to be mapped — ear-specific with insert earphones.