Glossary

A hearing aid worn behind the pinna with sound delivered through tubing to an earmould. The most powerful and flexible style, suitable for all losses and for children.

A device that delivers sound as skull vibration, bypassing the outer and middle ear. Used for conductive/mixed losses, atresia or draining ears, and single-sided deafness.

Independent frequency bands within which gain and compression are set, letting the response be shaped to the audiogram.

An implant that bypasses damaged hair cells and electrically stimulates the auditory nerve, for severe-to-profound sensorineural loss with limited benefit from hearing aids.

Aids custom-moulded to fill the ear or canal. Cosmetically discreet, but limited space and small batteries cap their power and features.

Algorithms that reduce gain in channels dominated by steady noise. Improves comfort and listening effort more than raw intelligibility.

Two or more microphone ports combined to attenuate sound from behind and the sides, improving the signal-to-noise ratio for sound in front — the most robust feature for speech in noise.

A soft, non-custom tip on a RIC or thin-tube aid. Open domes vent the canal, reducing occlusion and suiting milder high-frequency losses, at the cost of available gain.

A custom-fitted coupling that seals the ear canal, allowing maximum gain without feedback — needed for more severe losses.

Shifting high-frequency energy into a lower region where residual hearing is better — useful for steeply sloping losses or high-frequency dead regions.

The amount (in dB) by which a hearing aid amplifies sound. Modern aids apply different gain at different frequencies and input levels.

An implant that drives the ossicular chain or round window directly, for selected sensorineural or mixed losses where conventional aids are poorly tolerated.

The boomy, hollow quality of one's own voice when the ear canal is sealed. Reduced by venting (open fittings).

Confirming real-world benefit with standardised self-report tools such as the APHAB and the International Outcome Inventory for Hearing Aids.

The gain a validated formula prescribes for each frequency and input level. NAL-NL2 targets comfortable intelligibility (adults); DSL maximises audibility (children).

Measuring the aided output at the eardrum with a probe microphone and adjusting the aid to match the prescription target — the step that makes a fitting correct.

A behind-the-ear aid with the receiver moved into the ear canal on a thin wire. Discreet, with a wide fitting range — the most commonly fitted style today.

Applying more gain to soft inputs and less to loud ones, fitting the wide range of everyday sound into the reduced dynamic range of an impaired ear. Set by a compression threshold (knee) and ratio.