Book an appointment

Hearing Care Glossary

With the tremendous developement happening within the Hearing Aid indusrtry, new Hearing Aids features and products being introduced more often than ever before, there is an increasing number of related terms that we all find difficult to understand. In case you are struggling to understand what a particular term means, here you will find a Hearing Care Glossary with a brief explanation for all terms.


Acoustic Neuroma – A tumor, usually benign, which develops on the hearing and balance nerves and can cause gradual hearing loss, tinnitus, and dizziness, It normally only affects one ear.

Acquired Deafness – Loss of hearing that occurs or develops sometime in the course of a lifetime, but is not present at birth.

Accuvoice System – Accuvoice system is used to control the low frequency sounds so that your voice does not sound hollow.

Activity Analyzer – Activity Analyzer helps the Hearing Aid Dispenser to adjust the Hearing Aid to the users lifestyle by tracking the sound environments they are in.

Auditory Nerve – Eighth cranial nerve that connects the inner ear to the brain.Auditory Perception – Ability to identify, interpret, and attach meaning to sound.

Auditory Processing Disorder (APD) – Inability of an individual with normal hearing and intelligence to differentiate, recognise, or understand sounds normally.

Autoimmune Hearing Loss – Hearing loss when one’s immune system produces abnormal antibodies that react against the body’s healthy tissues. May be associated with tissue-causing disease, such as rheumatoid arthritis or lupus.

A/D (Analog to Digital) Converter – A/D Converter is a part of the chip that converts sounds into signals that the chip can recognize.

Adaptive Directional Microphone – Its a Hearing Aid microphone thats turns on when needed to pick up sound stright ahead over sound on other side.

Adaptive Directional Microphone Soft Switching – Its a Adaptive Directional Microphone with a feature to make the change in sound pickup less obvious for user.

Adaptability – Adaptability is the ability of a Hearing Aid Device to change its setting based on the listener’s environment.

Advanced AquaTex – Its an advanced moisture protection technology that makes the Hearing Aids highly water resistant inside and outside.

Advanced Noise Reduction – A more technologically advanced noise reduction system.

Algorithm – The procedure or formula a digital processor uses to calculate what needs to be done with sound as it goes through your hearing aid.

Aliasing – Occurs when a sound is not converted properly from analog to digital. The sound is reconstructed at a different frequency causing distortion.

American Speech Language Hearing Association (CCC-A) – An organization that provides standards for certification of audiologists. CCC-A designates an ASHA certified audiologists.

Amplifier (Amplification) – An electronic component that increases the loudness of sound.

Analogue Hearing Aid – A basic hearing aid that amplifies sound based on your audiogram.

Anti-Aliasing Filter – Filter within a digital chip that prevents aliasing.

Articulation Index Weighted Directivity Index (AI-DI) – A means to calculate the benefit of a directional microphone system.

Artificial Intelligence – term used by Oticon to describe their hearing aids ability to make changes without the wearer doing anything.

Assistive Devices – Tools and devices such as amplified telephones, alarms, alerting devices, or FM systems used to help people hear to perform daily actions, tasks, and activities.

Asymmetrical Hearing Loss – the degree of hearing loss in one ear is greater than the other.

Assistive Listening Devices: Instruments that amplify and transmit sound to help people sufferring Hearing Loss

Audibility – the level at which a sound can be heard.

Audiologist – a Masters ( MS ) or Doctorate ( AuD ) level professional with an educational focus in hearing sciences and hearing disorders.

Audiogram – a chart used to plot an individuals scores from a hearing test.

Audiometer – Electronic equipment used to perform a hearing test.

Automatic Telephone Solutions: A technology that automatically detects telephone use optimizes the acoustic frequency for enhanced experience.

Automatic Telecoil – programmable telecoil that activates automatically when a telephone is placed near.

Automatic Volume Control – the hearing aid automatically adjusts the volume for the wearer.


Balance – A biological system that enables individuals to know where their bodies are in the environment and to maintain a desired position. Normal balance depends on information from the labyrinth in the inner ear, from other senses such as sight and touch, and from muscle movement.

Balance Disorder – Disruption in the labyrinth, the inner ear organ that controls the balance system, which allows individuals to know where their bodies are in the environment. The labyrinth works with other systems in the body, such as the visual and skeletal systems, to maintain posture.

Background Noise – generally refers to the presence of other sound in an environment that is not the speech one is trying to hear.

Band – a range of frequencies that can be adjusted in a hearing independent of other frequencies

Bandwidth – the total area of frequency that a hearing amplifies generally from about 125Hz to 5500KHz.

Barotrauma – Injury to the middle ear caused by a rapid change of air or water pressure.

Battery – the power source for a hearing aid

Behind the Ear Hearing Aid (BTE) – style of hearing aid in which the components are placed behind the ear and the sound is delivered to the ear through a tube connect to an ear mold.

Bilateral Hearing Loss – a hearing loss in both ears Bluetooth – a type of wireless connection for electronic devises.

Bone Conduction Hearing Aid – a hearing aid that transfers sound through the skull instead of the ear canal.


Cerumen – Earwax

Cholesteatoma – An abnormal accumulation and pocketing of dead cells in the eardrum, which can often be surgically repaired.

Channel – a section of frequencies controlled by the hearing aids compression circuitry. Hearing aids can have as few as 1 channel and as many as the manufacturer wants to use.

Circuit Board – the piece inside the hearing aid that contains the digital chip Clinic – a professional medical oriented office.

Clock Generator – a circuit that provides the timing signal to synchronize the hearing aids operations.

Completely In Canal Hearing Aid (CIC) – the smallest style of hearing aid in which all or nearly all of the aid is placed inside the ear canal.

Cochlea – small snail shaped organ in which sound is processed and then sent to the brain. Cochlear Implant – type of hearing devise which part of is surgically connected to the cochlea and embedded in the skull. The other part is plugged into the port in the skull and contains the hearing aid portion.

Cognition – Thinking skills that include perception, memory, awareness, reasoning, judgment, intellect, and imagination.

Compression – a type of circuitry that is used to keep soft sounds audible and loud sounds comfortable.

Conductive Hearing Loss – Hearing Loss due to damage to the conductive portion -of the auditory system such as the eardrum or the bones in the middle ear.


D/A (Digital to Analog) Converter – changes the digital signal coming out of the amplifier into an analog sound that we can understand.

Data Logging – feature in some digital products that keeps a record of what kind of environments the user has been exposed to, battery life, hours of usage, etc., and may even make recommendations for adjustments.

Deaf – a person that is not able to perceive sound and / or understand speech, even when amplified.

Decibel (dB) – a measurement of the loudness of a sound Digital – a type of amplifier system that changes analog sound into a series of numbers for processing.

Digital Bionics – Phonak product name for a digital system that claims to mimic natural hearing,

Digital Signal Processor – a microprocessor that converts analog sound to digital signal.

Directional Microphone – A directional microphone is one that picks up sound from a certain direction, or a number of directions, depending on the model involved.

Digital Processor – see digital signal processor

Digital Speech Enhancement – the enhancement of speech signals by a digital processor to make speech more readily distinguished from noise.

Digital Surround Zoom – Phonak name for an adaptive directional microphone system.

Direct Audio Input – generally only available on BTE hearing aids, enables the wearer to directly connect an electronic sound source to their hearing aid.

Directional Imaging (PDI) – Starkey name for their directional microphone system.

Directional Microphone – multiple microphone system that amplifies sound from the front mor than sound from the rear for better hearing in noise.

Dual Band Directional Microphone – a directional microphone system that separates high and low frequencies, providing more emphasis on high frequency for better speech understanding.

D3 Directional Microphones – Sonic Innovations brand name for the directional microphone system used in their Innova product.

Directional Speech Detector (DSD) Directional Microphones – Directional Microphone system used in Starkey Destiny and Microtech Radius products.

Directional Polar Pattern – the area in relation to the head in which a directional microphone provides full amplification.

Disposabl Hearing Aid – a hearing aid designed to be worn and then thrown away when the battery dies. Dither – noise added to sound to reduce distortion Dynamic Range – the range between wear a person begins to hear sound and sound becomes uncomfortable.


E2E Wireless Communication – Siemens product that enables one hearing aid to make the same adjustments to the other hearing aid. Turn up the volume on one and it will automatically adjust the volume on the other aid.

Ear – the organ of hearing comprised of the outer ear, middle ear, and inner ear, but is more commonly used to refer to the portion of the ear that is visible, the pinna.

Ear Canal – channel on the side of the head that the pinna directs sound down to the eardrum.

Ear Drum – the tympanic membrane – thin membrane that separates the outer ear from the middle ear; sound vibrates the membrane which transfers the energy to the bones of the middle ear.

Ear Wax (Cerumen) – glandular excretion in the ear canal which is designed to help keep foreign objects from entering the ear canal.

Ear Infection – Presence and growth of bacteria or viruses usually in the middle ear.

Earmold – a lucite or silicon piece, usually custom made, that is inserted in the ear in order to connect a hearing aid or for hearing protection.

Echo Block – component in Phonak Savia that is designed to reduce reverberated sound, or echo.

EEPROM (Electrical Erasable Programmable Read-Only Memory) – the memory area of a hearing aids digital processor. ePocket Remote Control – Siemens remote control.


Feedback – the whistling sound that occurs when sound from a speaker loops back to the microphone.

Active Feedback Intercept – Starkey’s Destiny and Micotech’s Radius feedback cancellation product. Feedback Cancellation – the removal of feedback by producing a signal exactly opposite of the feedback signal.

Feedback Suppression – control of feedback by reducing the frequency where the feedback has occurred.

Fluctuating Hearing Loss – hearing loss that does not stay constant but is improved on some days and worse on others.

Frequency – the measurement of the number of times an event occurs in a specific time. The more often the higher the frequency.

Frequency Band – in hearing aids refers to the divisions of frequencies that can be adjusted for volume independently from other frequency bands.

Full Shell Hearing Aid (FS) – style of hearing aid that fills the bowl of the ear.


Gain – the volume added to a sound after amplification.

Granulation Noise – audible distortion in amplified sound.

Group Delay – the time delay between the input and output of a sound.


Hair Cells – Sensory cells of the inner ear, which are topped with hair-like structures (stereocilia), which transform the mechanical energy of sound waves into nerve impulses.

Half Shell Hearing Aid (HS) – style of hearing aid that fills approximately half of the bowl of the ear.

Hearing – the transfer of sound through the auditory system ( outer, middle, and inner ear ) to the brain.

Hearing Aid – an electronic devise used to improve damaged hearing.

Hearing Loss – Disruption in the normal process that may occur in either the outer, middle, or inner ear, whereby sound waves are not conducted to the inner ear, converted to electrical signals and/or nerve impulses are not transmitted to the brain to be interpreted as sound. Learn more about hearing loss.

Hearing Protection – products or strategies used to help to prevent noise-induced hearing loss or water from entering the ear canal.

Hereditary Hearing Impairment – Inherited hearing loss that is passed down through the family.

Hearing Test – series of tests performed with an audiometer that measures a persons hearing loss based on subjective response.

Hearing Loss – any reduction of a persons ability to hear sound below a sound level of 25 decibels between the ranges of 250 Hertz and 8000 Hertz.

Hertz (Hz) – measurement of the speed of a sound wave, one cycle per second = 1Hz High

High Power BTE – behind the ear hearing aid designed for hearing losses in the severe to profound range.

High Tone – high frequency sounds such as a soft s or f, crickets, children’s voices, treble.


Impression – a silicon cast of the shape of the ear and canal used to make custom hearing aids and ear molds. Intelligibility- how easily a sound, especially speech, is understood.

Inner Ear – Part of the ear that contains both the organ of hearing (the cochlea) and the organ of balance (the labyrinth).

In The Canal Hearing Aid (ITC) – style of hearing aid that resides primarily in the ear canal, but also extends into the bowl of the ear.

In The Ear Hearing Aid (ITE) – a style of hearing aid that fills the bowl of the ear (also called full shell)

Inverted Phase Feedback Canceller – a more advanced form of phase cancellation with improved performance. (see phase cancellation).


Labyrinth – Organ of balance located in the inner ear. The labyrinth consists of three semicircular canals and the vestibule.

Labyrinthitis – Viral or bacterial infection or inflammation of the inner ear that can cause dizziness, loss of balance, and temporary hearing loss.

Listening Program – an individual memory program in a digital hearing aid with multiple memories accessed through a push button or remote control.

Listening Environment – another term for listening program.

Low Frequency – sounds on the lower end of the speech frequency range. Perceived as low tones or bass, vowels are generally low frequency.

Low Frequency Roll Off Algorithm – circuitry that reduces low frequency amplification when activated to reduce background noise.

Low Tone – low frequency sounds such as vowels and hard consonants, bass.


Mastoid – Hard, bony structure behind the ear.

Mastoid Surgery – Surgical procedure to remove infection from the mastoid bone.

Manual Volume Control- the wearer adjusts the volume setting.

Megahertz (Mhz) – 1 million hertz.

Memory (Memories) – the area within the digital circuit that stores the information programmed for your hearing loss. Some hearing aids have more than one memory. The additional memories are programmed for specific situations such as noise or telephone use.

Memory Change Indicator – a beep signal that is given to let the wearer know when the have pushed their button and changed memories.

Meniere’s Disease – affects the membranous inner ear and is characterized by deafness, dizziness (vertigo), and ringing in the ear (tinnitus).

Mild Hearing Loss (20 -40 decibels) – where the softest sound perceptible at any frequency tested falls between 20 – 40 decibels.

Mixed Hearing Loss – a combination of sensorineural and conductive hearing loss. (see sensorineural and conductive)

Meningitis – Inflammation of the meninges, the membranes that envelop the brain and the spinal cord; may cause hearing loss or deafness.

Middle Ear – Part of the ear that includes the eardrum and three tiny bones (ossicles) of the middle ear, ending at the oval window that leads to the inner ear.

Micro Mould – a small, customised ear mould which fits on the end of the speaker of a CRT/ RITE style hearing aid to enable more low frequency amplification or a more secure fit.

Moderate Hearing Loss (40-60 decibels) – where the softest sound perceptible at any frequency tested falls between 40 – 60 decibels.

Multi-band Dual Mode – Oticon’s dual band directional microphone system in their Synchro product.

Multi-band Adaptive Directional Microphones – directional microphone systems that are capable of suppressing more than one sound source at a time in different frequencies.

Multi Channel Directional Optimization – Siemens’ multiple channel directional microphone system in the Acuris product line.

Mini Canal Hearing Aid – style of hearing aid slightly larger than a CIC and smaller than an ITC.


Nanoscience – studying and working with matter on an ultra small scale.

Noise – sound perceived as unwanted

Noise-induced Hearing Loss – Hearing loss caused by exposure to very loud sounds, either very loud impulse sound(s) or repeated exposure to sounds over 90-decibel level over an extended period of time that damage the sensitive structures of the inner ear.

Noise Reduction – reducing the perception of noise.


Omnidirectional – type of microphone that picks up sound from all around.

Otitis Media – Inflammation of the middle ear caused by infection.

Otoacoustic Emissions – Low-intensity sounds produced by the inner ear that can be quickly measured with a sensitive microphone placed in the ear canal in individuals with normal hearing. Often used to screen the hearing of infants.

Open Ear Acoustics – method of fitting hearing aids so that the ear canal is left as open as possible.

Open Ear Hearing Aid – a hearing aid designed to fit over the ear with a thin tube or wire running into the ear, and a small, soft plastic tip. The tip has holes to keep from blocking the ear canal so that the user does not feel plugged. Open Ear hearing aids are primarily used for high frequency hearing loss.

Otosclerosis – Abnormal growth of bone around the ossicles and the inner ear. This bone prevents structures within the ear from working properly and causes hearing loss. For some people with otosclerosis, the hearing loss may become severe, but often the hearing can be improved by surgery or hearing aids.

Ototoxic Drugs – Drugs that can damage the hearing and balance organs located in the inner ear.

Outer Ear – External portion of the ear, consisting of the pinna, or auricle, and the ear canal.


Phase Cancellation – cancellation of sound by creating a sound exactly opposite.

Postlingually Deafened – Individual who becomes deaf after having acquired language.

Prelingually Deafened – Persons either born deaf or who lost his or her hearing early in childhood, before acquiring language.

Presbycusis – Loss of hearing that gradually occurs because of changes in the inner or middle ear in individuals as they grow older the type of hearing loss often associated with presbycusis is a sensorineural hearing loss.

Processor – the part of a digital chip where information is interpreted and changed based on the instructions that have been programmed into the processor.

Processing Power – how fast a processor works. Profound Hearing Loss (over 80 Decibels) where the softest sound perceptible at any frequency tested falls at 80 decibels or worse.

Profound Hearing Loss (over 80 decibels) – where the softest sound perceptible at any frequency tested falls at 80 decibels or worse.

Program – refers to a set of instructions given to the processor.

Programmable Telecoil – a telecoil that is connected to one of the memory slots of a hearing aid and can be programmed to the users needs apart from the other memories.

Programming – creating and sending the program to the processor. Progressive Hearing Loss – a hearing loss that becomes progressively worse over time.

Progressive Hearing Loss – a hearing loss that becomes progressively worse over time.

PROM (Programmable Read-Only Memory) – the memory portion of the hearing aid in which programming information is stored.

PxP Matrix (Extreme Power Matrix) – Starkey DaVinci PxP, a brand name for their super high power hearing aid.


Receiver – the speaker of the hearing aid.

Reverberation – sound being reflected off of a surface.


Sampling Rate – the rate at which incoming analog sounds are taken and converted to digital form.

Sensorineural Hearing Loss – hearing loss due to damage to the inner ear (cochlea) or the nerve pathway from the cochlea to the brain.

Severe Hearing Loss (60-80 decibels) – where the softest sound perceptible at any frequency tested falls between 60 – 80 decibels.

Shell – The outer portion of the hearing aid that is custom formed to fit the ear.

Sign Language – Method of communication for people who are Deaf in which hand movements, gestures, and facial expressions convey grammatical structure and meaning.

Sound Waves – Sound is made up of molecules of air that move and when they push together the form waves.

Sound Navigation – automatic feature in Phonak Savia that changes the hearing aid between 4 different programs dependent on the environment.

Speech Comfort System – Siemens noise management system in the Triano products.

Speech Understanding – also called discrimination, refers to the ability to understand speech when amplified to a comfortable level.

Stable Hearing Loss – a hearing loss that has not changed for several years.

Sudden Hearing Loss – a hearing loss that occurs with a rapid onset requiring immediate medical treatment.

Symmetrical Hearing Loss – hearing loss that is the same or very similar in both ears.


Tinnitus – Perceived sensation of a sound in the ears or head in the absence of an external similar sound. It can be associated with many forms of hearing loss and noise exposure but can equally occur when ones hearing is completely within normal limits.

Telecoil – devise in a hearing aid that can connect with the magnetic coils of a telephone and transgfer the sound through the hearing aid without feedback.

Tone – the perceived frequency of a note or sound.

TriState Noise Management – the noise management system in Oticon Sumo DM which combines VoiceFinder speech detection and noise management.

Tympanoplasty – Surgical repair of the eardrum (tympanic membrane) or bones of the middle ear.


Unilateral Hearing Loss – hearing loss in only one ear.


Vent – an air channel in the hearing aid or earmold to alleviate pressure and reduce low frequency amplification.

Voice Aligned Compression – multiple band compression strategy in Oticon Syncro II.

VoiceFinder – noise management system in Oticon Adapto.

Voice Priority Processing – processing strategy that combines adaptive directional microphones, noise management, and compression to provide maximum speech understanding and comfort.

Volume Control – component of the hearing aid that turns the volume up or down.

Vertigo – Illusion of movement; a sensation as if the external world were revolving around an individual (objective vertigo) or as if the individual were revolving in space (subjective vertigo).

Vestibular System – System in the body that is responsible for maintaining balance, posture, and the body’s orientation in space. This system also regulates locomotion and other movements and keeps objects in visual focus as the body moves.


Warp Processing – a type of digital processing that improves execution time and energy consumption

Warranty – the period of time for which a hearing is covered for repairs and/or loss and damage.

Wide Dynamic Range Compression (WDRC) – hearing aid processing type that works to keep soft sounds audible and loud sounds comfortable.

Wind Noise Manager – device within a digital processor that reduces the sound of wind noise on the microphone.