Air conduction
Testing or amplification that sends sound through the ear canal, eardrum and middle ear to the cochlea.
90 learning terms
Hearing & Technology Glossary
Use the glossary to decode a report or product description. Definitions teach the term without turning it into a diagnosis or product recommendation.
Air–bone gap
A difference between air- and bone-conduction thresholds that can suggest a conductive component when the test is reliable.
Audiogram
A graph showing measured hearing thresholds across frequencies, usually in dB HL.
Audiologist
A hearing professional trained to assess hearing and balance and provide rehabilitative services within the person’s license and setting.
Auditory brainstem response
An electrophysiologic test that records nervous-system responses to sound through scalp electrodes.
Auracast
A Bluetooth LE Audio broadcast capability designed to let compatible receivers join an audio broadcast.
Behind-the-ear hearing aid
A hearing aid with the main case behind the ear and sound delivered through tubing or a receiver.
Bilateral
Affecting or involving both sides.
BiCROS
A system that routes sound from a poorer-hearing side while also amplifying sound for the better-hearing ear.
Bluetooth LE Audio
A newer Bluetooth audio architecture using the LC3 codec and supporting capabilities such as broadcast audio.
Bone conduction
Transmission or testing that sends vibration through the skull to stimulate the cochlea.
Captioned telephone
A telephone service or device that displays text representing the other party’s speech.
CART
Communication access real-time translation provided by a trained captioner for live access.
Cochlea
The fluid-filled inner-ear organ that converts mechanical vibration into neural activity.
Cochlear implant
An implanted system that electrically stimulates the auditory nerve after specialist candidacy evaluation.
Completely-in-canal
A small custom hearing aid positioned mostly within the ear canal.
Conductive hearing loss
Reduced sound transmission through the outer or middle ear, identified through a complete evaluation rather than one test alone.
CROS
A routing system that sends sound from a poorer-hearing side to a receiver at the better ear.
dB HL
Decibels hearing level, a calibrated audiometric scale used to plot hearing thresholds.
Directional microphone
A microphone system designed to give more emphasis to sound arriving from selected directions.
DM system
A digital modulation remote-microphone system used to send a talker’s signal to a listener.
Domes
Replaceable earpieces used on many receiver-in-canal and thin-tube hearing aids.
Ear-canal volume
A tympanometry estimate of the air space between the probe and eardrum or another open endpoint.
Ear hook
The curved part of many BTE hearing aids that connects the case to tubing.
Earmold
A custom or standard earpiece that couples a hearing device to the ear.
Eustachian tube
The passage involved in middle-ear pressure regulation and drainage toward the throat.
Feedback
A whistling or oscillating sound that can occur when amplified output returns to a microphone.
FM system
A remote-microphone system using frequency-modulated radio transmission.
Frequency
The rate of sound vibration, measured in hertz and perceived broadly as pitch.
Hearing aid
A wearable medical device intended to amplify sound for a person with hearing loss.
Hearing loop
A system that sends audio as a magnetic signal that can be received by a telecoil.
Hearing threshold
The lowest level at which a person responds to a test signal under defined conditions.
Hertz
Cycles per second, the unit used for sound frequency.
In-the-ear hearing aid
A custom hearing aid whose components sit in a shell within the outer ear.
Invisible-in-canal
A very small custom hearing aid positioned deeply in the ear canal when anatomy permits.
LC3
The Low Complexity Communication Codec used by Bluetooth LE Audio.
Live captions
Text generated while speech is occurring, either automatically or by a trained provider.
Localization
The ability to judge where a sound is coming from using timing, level and spectral cues.
Masking
Test noise delivered to the non-test ear when needed to prevent it from responding for the test ear.
Mixed hearing loss
A hearing loss with both conductive and sensorineural components.
Occlusion effect
The plugged or boomy perception of one’s own voice that can occur when the ear canal is sealed.
Otoacoustic emissions
Low-level sounds measured in the ear canal that provide information about cochlear outer hair-cell function.
Otoscopy
Visual examination of the ear canal and eardrum.
OTC hearing aid
An over-the-counter air-conduction hearing aid for adults with perceived mild-to-moderate hearing loss under FDA requirements.
Peak pressure
The ear-canal pressure at which a tympanogram reaches its principal peak.
Probe microphone measurement
A measurement using a thin tube in the ear canal to assess hearing-aid output near the eardrum.
Pure-tone average
An average of selected pure-tone thresholds used for particular clinical or administrative purposes.
Real-ear measurement
A common term for probe-microphone verification of hearing-aid output in an individual ear.
Receiver
The miniature speaker that converts an electrical hearing-aid signal back into sound.
Receiver-in-canal
A hearing-aid style with the receiver in the ear canal and the remaining case behind the ear.
Remote microphone
A microphone placed near a talker that sends its signal to a listener’s receiver or hearing device.
Reverberation
Persistence and reflection of sound in a room after the direct sound is produced.
Sensorineural hearing loss
Hearing loss involving the cochlea or neural pathway, interpreted through a complete evaluation.
Signal-to-noise ratio
The level relationship between a desired signal and competing background sound.
Soundfield testing
Testing through loudspeakers rather than ear-specific earphones, often used to assess aided performance.
Speech recognition
A measured ability to identify speech material under specified presentation conditions.
Speech reception threshold
The level at which a person can identify a defined proportion of familiar speech material.
Sudden hearing loss
A rapid hearing change that warrants prompt medical assessment rather than self-treatment.
Telecoil
A small coil in a hearing device or receiver that detects compatible magnetic audio signals.
Tinnitus
Perception of sound such as ringing or buzzing without a corresponding external source.
Tympanogram
The graph produced by tympanometry as ear-canal pressure changes.
Tympanometry
A measurement of acoustic admittance or related middle-ear response while ear-canal pressure is varied.
Type A tympanogram
A teaching label for a tympanogram with a peak near expected middle-ear pressure.
Type Ad tympanogram
A teaching label for a tympanogram with unusually high measured mobility.
Type As tympanogram
A teaching label for a shallow-peaked tympanogram with reduced measured mobility.
Type B tympanogram
A flat tympanogram without a clear pressure peak; ear-canal volume is essential to interpretation.
Type C tympanogram
A tympanogram with a peak at negative ear-canal pressure.
Unilateral
Affecting or involving one side.
Vent
An opening through an earmold or custom shell that affects pressure, comfort and acoustic response.
Wax guard
A replaceable filter intended to limit earwax reaching a hearing-aid receiver.
Word-recognition score
Performance on a particular speech list at a specified presentation level and test condition.
Acoustic reflex
A middle-ear muscle response measured under controlled sound conditions and interpreted with the rest of the audiologic test battery.
Auditory processing
How the nervous system uses auditory information; assessment requires more than a standard audiogram and must consider language, attention and cognition.
Binaural hearing
Use of input from both ears to support localization and listening in complex environments.
Compression
A hearing-aid process that changes gain as input level changes so soft, average and loud sounds can fit within a reduced listening range.
Data logging
Device-recorded use information that may summarize wearing time, environments or adjustments without explaining the user’s complete experience.
Electrocochleography
A measurement of electrical responses generated by the cochlea and auditory nerve region after sound stimulation.
Functional gain
Aided soundfield threshold improvement compared with unaided thresholds; it does not replace probe-microphone verification.
Hyperacusis
Reduced tolerance for ordinary environmental sounds that requires individualized assessment rather than simply stronger hearing protection.
Interaural attenuation
Reduction in sound energy as a test signal crosses from one ear to the other, relevant when deciding whether masking is needed.
Listening effort
The mental resources used to understand sound, which may remain high even when accuracy appears acceptable.
Maximum power output
A hearing-aid output limit intended to help control how loud amplified sound can become.
Noise reduction
Signal processing intended to reduce selected steady or diffuse noise characteristics; it does not remove every competing talker.
Occluding earmold
An earmold with limited venting that can support greater low-frequency output and feedback stability while changing own-voice perception.
Probe tube
The thin flexible tube placed in the ear canal during real-ear measurement.
Rechargeable hearing aid
A hearing aid using an integrated or replaceable rechargeable power system with device-specific charging and service requirements.
Speech-in-noise test
A structured measure of speech understanding with competing noise under specified signal and scoring conditions.
Threshold shift
A measured change in hearing thresholds that must be considered with test reliability, method and clinical context.
T-coil program
A hearing-device program that receives compatible magnetic audio through a telecoil, sometimes with the microphone also active.
Visual alert
A light, screen or other visual signal used to supplement or replace an audible notification for a defined event.
How to use a definition
A label is only one piece of a hearing evaluation or technology decision. Follow the related guide for examples, measurement limits and a useful next action. If wording on an individual report is unclear, ask the professional who performed the test.