Glossary of Hearing Terms

Glossary of Hearing Terms A-Z

Glossary of Hearing Loss and Hearing Impaired Terms


Acoustic neuroma

A tumor, usually benign, which may develop on the hearing and balance nerves and can cause gradual hearing loss,tinnitus, and/or dizziness. (sometimes called vestibular schwannoma). Also see neurofibrometosis Type 2

Acquired deafness

The loss of hearing that occurs or develops some time during your lifespan but is not present at birth.

Age-related hearing loss

The most common form of hearing loss is called presbycusis, or age related hearing loss. One out of seven will experience this loss. Usually in both ears. It is called sensorineural hearing loss and affects the higher ranges of hearing.

Alport syndrome

Is a hereditary condition characterized by kidney disease, sensorineural hearing loss, and sometimes eye defects.

American Sign Language (ASL)

The manual language with its own syntax and grammar, used primarily by people who are deaf.


The amplifier takes sound received by a microphone, then transfers the sounds to an amplifier where it is processed and is then amplified and transmitted to the receiver or speaker in your ear.

Analog (hearing aid)

The analog was the first hearing aid on the market. Similar to a sound amplifier. Since then digital aids have almost taken over in sophistication and ability, with many more features and benefits. However, the older people disagree. They like their old analogs.

Assistive devices

Are the technical tools and devices such as alphabet boards, text telephones, or text-to-speech conversion software used to aid individuals who have communication disorders perform actions, tasks, and activities.

Attack and release times

Are for obtaining the best hearing aid auditory setting when there is an absorption of a sound increase (attack) and the time between the absorption of the sound decrease (release) for a more enjoyable hearing aid experience.


A health care professional who is trained to evaluate hearing loss and related disorders, including balance (vestibular) disorders and tinnitus, and to rehabilitate individuals with hearing loss and related disorders. An audiologist uses a variety of tests and procedures to assess hearing and balance function and to fit and dispense hearing aids and other assistive devices for hearing.


The audiogram is the result of your hearing test that details specific ranges and frequency thresholds of both your ears.


An electronic device for testing hearing of different intensities and frequencies that determine your hearing ability or inability.

Auditory Brainstem Response test (ABR test)

A test for brain functioning in comatose, unresponsive, etc., patients, and for hearing in infants and young children; involves attaching electrodes to the head to record electrical activity from the hearing nerve and other parts of the brain.

Auditory nerve

The eighth cranial nerve that connects the inner ear to the brainstem and is responsible for hearing and balance.

Auditory perception

The ability to identify, interpret, and attach meaning to sound.

Auditory prosthesis

A device that substitutes or enhances the ability to hear.

Audio shoe

A very small electronic device also known as an Audio Boot that can connect to your hearing aid through an audio port the connects with a behind the ear BTE aid that can be used for connecting to radio’s TV’s and music players and can also be used as an FM player as well.

AKA Audio boot. A small electronic device, that you can connect to your hearing aid using the Direct Audio Input (DAI) port. Typically, it fits the bottom of a BTE device and can be used as a stand-alone FM receiver or additional microphone. It can also be used as a connector for different audio sources like TV, music player etc (using cable, of course).

Augmentative devices

These are tools that help individuals with limited or absent speech to communicate, such as communication boards, pictographs (symbols that look like the things they represent), or ideographs (symbols representing ideas).

Aural rehabilitation

The techniques used with people who are hearing impaired to improve their ability to speak and communicate.

Automatic gain control

The component in a hearing aid that automatically limits the aids maximum volume. Most hearing aids come with this feature.

Autoimmune deafness

The individual’s immune system produces abnormal antibodies that react against the body’s healthy tissues.



Our 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

A 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.


An injury to the middle ear caused by a reduction of air pressure.


Are what supply power to the hearing aids. Zinc air constructed pill box or tablet sized batteries are very common and easily obtainable. There is currently a strong trend toward the rechargeable feature.

BTE (Behind the Ear Hearing Aids)

This describes the location of where the hearing aid rests or sits. A small flexible tube then carries to sound to an ear plug inside the ear canal.

Benign Paroxysmal Positional Vertigo (BPPV)

A balance disorder that results in sudden onset of dizziness, spinning, or vertigo when moving the head.

Brainstem implant

An auditory prosthesis that bypasses the cochlea and auditory nerve. This type of implant helps individuals who cannot benefit from a cochlear implant because the auditory nerves are not working.



The text display of spoken words, presented on a television or a movie screen, that allows a deaf or hard-of-hearing viewer to follow the dialogue and the action of a program simultaneously.

Central auditory processing disorder

This is the inability to differentiate, recognize, or understand sounds; hearing and intelligence are normal.


Hearing aids divide their frequency ranges into channels, or bands. For example if there were a frequency range of 1HZ to 1000HZ, you could divide that number into four channels or bands of 250HZ each. Then if your loss is in the top 250HZ of those four, then that band or channel could be individually tweaked for you to hear better in that particular frequency. Specific channels can also be filtered to manage noise in all the different frequencies.


The accumulation of dead cells in the middle ear, caused by repeated middle


Cleaning your hearing aid is as essential as cleaning your ears. They both work in an moist and waxy environment. The aid is a fragile device that needs regular maintenance. Check our ezine article about how Blue Indicating Silica Beads used for drying your hearing aid out, can cause cancer.


A cochlea is a snail shaped organ filled with fluid. The bones of the middle ear vibrate against it mechanically and move the fluid inside. The cilia, or hair cells in the cochlea translate that to an electrical signal that transmits it to the hearing nerve and onto the brain for decoding into sounds. Cilia malfunction is the most common form of hearing loss.

Cochlear implant

A medical device that bypasses damaged structures in the inner ear and directly stimulates the auditory nerve, allowing some deaf individuals to learn to hear and interpret sounds and speech.


The thinking skills that include perception, memory, awareness, reasoning,

Combined hearing loss

A hearing loss that combines a conductive hearing loss with a sensorineural hearing loss.

CIC (Completely In the Canal Hearing Aids)

This is a hearing aid that is located entirely in the ear canal. Even though advertisers say they are invisible, they still have to be removed by a clear plastic grip for removal. The chord or plastic tab are not invisible!


Compression allows you to hear a range of sounds that are compressed in between, just above a whisper to slightly less that a jet plane. The hearing aid compresses all sound into 50dB, or decibels, to 120dB instead of zero to above 130 dB.

Conductive Hearing Loss

A form of hearing loss caused by a dysfunction of the outer or middle ear. This kind of hearing loss is reversible and can be treated medically. It can also be the result of to much wax in your ears, fluid build up or structural damage.


The vowels are the A,E,I,O,and U’s. However, sounds that we make when restricting our air flow are when we use all the other letters, or consonants. Like, B,C,D,F,G, ect… Our ability to understand human speech is based on our ability to distinguish between all the different consonants.

Cued speech

The method of communication that combines speech reading with a system of handshapes placed near the mouth to help deaf or hard-of-hearing individuals differentiate words that look similar on the lips (e.g., bunch vs. punch) or are hidden (e.g., gag).

Cytomegalovirus (Congenital)

One of the group of herpes viruses that infects humans and can cause a variety of clinical symptoms, including deafness or hearing impairment; infection with the virus may be before or after birth.



A unit that measures the intensity or loudness of sound. It describes the power of the sound. 0dB is defined by the weakest sound a person can hear. And 120dB is the most.

Digital (Hearing aid)

A better way to process sounds. The sounds are transformed into smaller bits that can be manipulated to erase background sound as just one example of the features and benefits of digital aids.

Direct Audio Input (DAI)

A three pin plug, that you can find on many BTE hearing aids. DAI enables you to connect to other audio sources directly into your hearing aid. Like a phone, TV, PC or choice of music players.
Because it connects directly into the hearing aid, it bypasses the microphone and the T-coil and be far less sensitive to other noises. DAI is also used to connect Audio Shoes, also called Audio Boots.

Directional mechanism

A microphone that can be directed toward where the person wants to hear sounds from, and suppresses other surrounding sounds.


The physical unsteadiness, imbalance, and lightheadedness associated with balance disorders.


any disturbance of balance.


disruption in the smooth flow or expression of speech.


Ear drum

A very fragile membrane that goes from the outer ear and the middle ear. Sounds enter the ear canal, vibrating the ear drum that then transmits that sound energy to the hearing bones or ossicles in the middle ear. Puncturing an eardrum can be very painful.

Ear infection

The presence and growth of bacteria or viruses in the ear.

Ear mold

A tight silicon imprint of your ear size that connects to a behind the ear aid. This allows for a better control of the sounds the microphone picks up and eliminates a lot of feedback.


The yellow secretion from glands in the outer ear (cerumen) that keeps the skin

of the ear dry and protected from infection.

Eustachian tube

A small tube that connects the nasal cavity and pharynx to the middle ear It keeps the ear ventilated and regulates the air pressure inside it. If the nasal cavity is jammed with swelling or mucus the pressure regulating will not be at it optimum. It is one of the biggest reasons for hearing loss among infants, toddlers and kids.


A fluid in the labyrinth (the organ of balance located in the inner ear that consists of three semicircular canals and the vestibule).

Extended Wear Hearing Aid

Extended wear hearing aids are hearing devices that are non-surgically placed in the ear canal by a hearing professional. The extended wear hearing aid represents the first “invisible” hearing device.



That squeaky sound you can hear when a microphone absorbs a part of the amplified sound. For hearing aids, it happens when a tone or sound, that was already amplified, goes from inside the ear and finds its way to the microphone back on the outside of the ear. This causes the tone or sound to be amplified over and over again by the hearing aid and that eventually causes an irritating whistle.

Filter, Audio

An audio filter enables you to amplify certain frequencies and filter out the other frequencies so they will not be amplified. For instance, if you have only hearing loss on high frequencies, the lower frequencies will be filtered and will not be amplified so you’ll hear those specific tones or sounds in their natural form.

Filter or Shield

A part on the hearing aid located where the sound is transmitted to the ear canal that protects the device from ear wax and dirt. A clogged filter can be the cause of poor performance. They are easily replaced.


For the purpose of hearing aids, a frequency is the rate at which a sound vibration is measured per second and then constitutes a wave, either in a physical material as in sound waves, or in an electromagnetic field, as in radio waves or light.



Hair cells

Are the sensory cells of the inner ear, which are topped with hair-like structures, the stereocilia, and which transform the mechanical energy of sound waves into nerve impulses. Most sensorineural hearing losses are caused by damaged cilia or hair cell malfunction.


A series of events in which sound waves in the air are converted to electrical signals, which are sent as nerve impulses to the brain, where they are interpreted.

Hearing aid

An electronic device that brings amplified sound to the ear. A hearing aid usually consists of a microphone, amplifier, and receiver.

Hearing disorder

A disruption in the normal hearing process that may occur in 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.

Hearing loss

Hearing loss is generally characterized by a decrease in the ear’s sensitivity to hearing sounds. A person with hearing loss requires higher volumes of sound in order to hear well.

Hearing test

An audiologist usually performs this test in a sealed room from other noises to determine the frequencies you can hear and more specifically the frequencies you cannot. In a hearing test, they test frequencies from 250Hz to 8000Hz. Our hearing covers a wider range of frequencies that range from, 20Hz to 20000Hz.

Hereditary hearing impairment

Hearing loss that is passed down through generations of a family.

Herzt (Hz)

A unit to measure frequencies. A metronome that ticks 10 times a second is said to be ticking on a 10 Hertz frequency. A frequency is how low or how high we feel it. For example, bird’s tweet is high in frequency and a roaring motor is low in frequency.



A possible solution for strong hearing loss that a hearing aid cannot help you with. An implant is basically a very small hearing aid that is surgically implanted into your cochlea to assist with hearing.


Alterations in the pitch and prosody of spoken language to convey meaning.

Inner ear

A part of the ear that contains both the organ of hearing (the cochlea) and the organ of balance (the labyrinth).


Refers to the energy flow per unit area (audiology).

ITE (In The Ear)

A hearing aid that “seats” itself inside the outer ear.

ITC (In The Canal)

A hearing aid that is placed in the ear canal. The outer part can be seen on the entry into the canal.

ITC In-The-Canal, or ITE In-The-Ear (Half Shell): This is a smaller version of the full shell in-the-canal hearing aid. The half-shell is custom molded and fills the lower portion of the bowl-shaped area of your outer ear. This style is appropriate for mild to moderately severe hearing loss. A half-shell hearing aid is bigger than an in-the-canal hearing aid and is a little easier to handle than the smaller hearing aids

ITC In-The-Canal, or ITE In-The-Ear(Full Shell):

This type features the widest selection of user-controlled functions and comfort

features in the ear. An in-the-ear (full-shell) hearing aid is custom made and fills most of the bowl-shaped area of your outer ear. This style is helpful for people with mild to severe hearing loss. An in-the-ear (full-shell) hearing aid is more visible to others. They may pick up wind noise. However, it also contains some helpful features as well. Such as volume control, and are easier to adjust. They are generally easier to insert into and out of the ear. The ITC full shell uses larger batteries, which typically last longer and are easier to handle





An organ of balance located in the inner ear. The labyrinth consists of three semicircular canals and the vestibule.

Labyrinthine hydrops

Where there is an excessive fluid in the organ of balance (labyrinth); can cause pressure or fullness in the ears, hearing loss, dizziness, and loss of balance.


A viral or bacterial infection or inflammation of the inner ear that can cause dizziness, loss of balance, and temporary hearing loss.

Lip reading

A means hearing impaired people use for understanding. Even hearing people in difficult conditions use lip reading to some capacity. This talent can be developed and improved by anyone.


The ability to perceive where the sounds are originating from. It is based on the differences our two ears hear volume from, as the two ears hear sounds slightly differently.


The way in which a sound level is perceived. The same volume can be experienced differently by different people. Often people with hearing loss perceive medium volume sounds as unbearably loud.



The back portion of the temporal bone that contains the inner ear.

Mastoid surgery

A surgical procedure to remove infection from the mastoid bone.

Ménière’s disease

An inner ear disorder that can affect both hearing and balance. It can cause episodes of vertigo, hearing loss, tinnitus, and the sensation of fullness in the ear.


The inflammation of the meninges, the membranes that envelop the brain and the spinal cord; may cause hearing loss or deafness.


An electrical component that receives the sounds and voices from the surrounding area and turns them into electrical signals with the right frequency and amplitude.

Middle ear

The part of the ear that includes the eardrum and three tiny bones of the middle ear, ending at the round window that leads to the inner ear.



The ability of the brain and/or certain parts of the nervous system to adapt to new conditions, such as an injury.

Neural prostheses

Devices that substitute for an injured or diseased part of the nervous system, such as the cochlear implant.

Neural stimulation

To activate or energize a nerve through an external source.

Neurofibromatosis Type 1 (NF-1 von Recklinghausen’s)

A group of inherited disorders in which noncancerous tumors grow on several nerves that may include the hearing nerve. The symptoms of NF-1 include coffee-colored spots on the skin, enlargement, deformation of bones, and neurofibromas.

Neurofibromatosis Type 2 (NF-2)

Another group of inherited disorders in which noncancerous tumors grow on several nerves that usually include the hearing nerve. The symptoms of NF-2 include tumors on the hearing nerve which can affect hearing and balance. NF-2 may occur in the teenage years with hearing loss. Also see acoustic neurinoma.

Neurogenic communication disorder

Our inability to exchange information with others because of hearing, speech, and/or language problems caused by impairment of the nervous system (brain or nerves).

Noise-induced hearing loss

Noise canceling mechanism

The background noises that the hearing aid amplifies is one of the biggest problems for the device. Firms are constantly improving their noise cancellation mechanisms in order to improve this issue and to cancel some noises rather than amplify them. The hard part is to make the hearing aid distinguish between wanted sound and unwanted sounds.

Nonsyndromic hereditary hearing impairment

Hearing loss or deafness that is inherited and is not associated with other inherited clinical characteristics.



A substance that stimulates the sense of smell.

Open fit

This is a hearing aid that has a ventilation tunnel that goes through it. Therby allowing low tones to pass through it. It also amplifies the middle and high frequencies. This is good for a high tone hearing loss.


The act of smelling.


A device for estimating the intensity of the sense of smell.

Open-set speech recognition

Understanding speech without visual clues (speech reading).


or “Open-fit” hearing aids are small (BTE’s) behind-the-ear type devices. This type is characterized by a minimal amount of effect on how it resonates in the ear canal, and commonly leaves the ear canal as open as is possible. Quite often only being plugged up by a small speaker resting in the middle of the ear canal.

Otitis externa

An inflammation of the outer part of the ear extending to the auditory canal.

Otitis media

An inflammation of the middle ear caused by infection.

Otoacoustic emissions

The low-intensity sounds produced by the inner ear that can be quickly measured with a sensitive microphone placed in the ear canal.


A physician and or surgeon who specializes in diseases of the ears, nose, throat, and head and neck.


A physician or surgeon who specializes in diseases of the ear.


An abnormal growth of bone of 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.

Ototoxic drugs

Are drugs such as a special class of antibiotics, aminoglycoside antibiotics, and over the counter medications that can damage the hearing and balance organs located in the inner ear for some individuals.

Outer ear

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

Output or Sound Level

Is the signal strength coming from the hearing aid’s speaker. It is a result of the input signal plus the gain added by the hearing aid.


Perception (Hearing)

The process of knowing or being aware of information through the ear.

Perilymph fistula

A leakage of inner ear fluid to the middle ear that occurs without apparent cause or that is associated with head trauma, physical exertion, or barotrauma.


The study of speech sounds.

Postlingually deafened

An individual who becomes deaf after having acquired language.

Prelingually deafened

An individual who is either born deaf or who lost his or her hearing early in childhood, before acquiring language.


The loss of hearing that gradually occurs because of changes in the inner or middle ear in individuals as they grow older.


On many hearing aids there is an option to define what acoustic programs you want or need. Each program is for a different environment. For example, you can have program for noisy places like restaurants or a program for a concert. One for driving and one for watching TV. Usually, you can switch between the different programs with a button or a remote control. There are newer hearing aids that will learn your preferences and switch automatically from one program to the next.




A condition that sometimes appears along with hearing loss. This is where a person with hearing loss feels that voices and sounds are louder than how they are actually being perceived by a hearing person.

The consequences of this condition is that the hearing range of a person with hearing loss is smaller comparing to a fully hearing person. On the one hand, you can’t hear quiet voices or noises, and on the other hand, you can’t stand loud ones either.

Real Ear Measurement (REM)

Hearing aids are developed on a generic ear that is supposed to cover all ear types. The REM verifies that the hearing aid functions as expected once it is in your own ear.

Round window

A membrane that separates the middle ear and inner ear.


Sensorineural hearing loss

The most common hearing loss caused by damage to the sensory cells and/or nerve fibers of the inner ear. It can be a result of aging, exposure to loud noise, injury, disease, oto-toxic drugs or an inherited condition.

Signal to Noise Ratio (SNR)

The ratio between what we want to hear and the background unwanted noises. Generally speaking, the better the signal to noise is, the better speech understanding gets.

Sign language

A method of communication for people who are deaf or hard of hearing in which hand movements, gestures, and facial expressions convey grammatical structure and meaning. rhinitis.

Sound vocalization

The ability to produce voice.


The part of the hearing aid that transforms an amplified electrical signal into acoustic energy, that sends the sounds into the ear canal.

Specific language impairment (SLI)

A difficulty with language or the organized-symbol system used for communication in the absence of problems such as mental retardation, hearing loss, or emotional disorders.


Our spoken communication.

Speech disorder

Any defect or abnormality that prevents an individual from communicating by means of spoken words. Speech disorders may develop from nerve injury to the brain, muscular paralysis, structural defects, hysteria, or mental retardation.

Speech processor

The part of a cochlear implant that converts speech sounds into electrical impulses to stimulate the auditory nerve, allowing an individual to understand sound and speech.

Speech-language pathologist

A health professional trained to evaluate and treat people who have voice, speech, language, or swallowing disorders (including hearing impairment) that affect their ability to communicate.

Sudden deafness

The loss of hearing that occurs quickly due to such causes as explosion, a viral infection, or the use of some drugs.

Sudden Sensorineural Hearing Loss
There is another type of sensorineural hearing loss called Sudden Sensorineural Hearing Loss (SSHL). This type of hearing loss may occur very suddenly or over the course of a few days. It is imperative to see an otolaryngologist or ear Doctor immediately. A delay in treating this condition of only three days will decrease your chances to reclaim or improve the hearing loss with medications.

Syndromic hearing impairment

A hearing loss or deafness that, along with other characteristics, is inherited or passed down through generations of a family.


The telecoil (T-Coil)

A copper loop or coil of wire that surrounds a room and turns sound waves into an electromagnetic field, then converts back in sound by the T-Coils in hearing devices allowing the user to hear music directly into their aids with little or no dreaded background noises.

Threshold (hearing)

The quietest sound a human can hear is defined as a hearing threshold. Hearing thresholds are measured in decibels (dB) ranging from 250Hz to 8000Hz which cover most human speech.


The sensation of a ringing, roaring, or buzzing sound in the ears or head. It is often associated with many forms of hearing impairment. Noise exposure and inner ear infections are but two predisposing conditions which can lead to the development of tinnitus.


A tactile sense; the sense by which contact with the skin or mucous membrane is experienced.


A tiny and transparent tube that conducts the sounds from the case of the hearing aid to the ear mold or bud. It should be flexible and clear and needs replacing when it gets yellowish and rigid.


A surgical repair of the eardrum (tympanic membrane) or bones of the middle ear.


UCL (Un Comfortable Level)

This is the maximum sound level that a patient can experience and be comfortable with. If the sound is just a little louder it is considered un- comfortable.

Usher syndrome

A hereditary disease that affects hearing and vision and sometimes balance.



A vent is a hole though your ITE In The Ear hearing aid or though your ear mould. If you completely plug up your ear canal, then it can feel like you are “in a drum”, even if the sound is being passed through by the hearing aid. That feeling is called”occlusion”.


The 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 Neuronitis

An infection at the vestibular nerve.

Vestibular system

The 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.


A bony cavity of the inner ear.

Vibrotactile aids

The mechanical instruments that help individuals who are deaf to detect and interpret sound through the sense of touch.

Vocal cord paralysis

An inability of one or both vocal folds (vocal cords) to move because of damage to the brain or nerves.

Vocal cords (Vocal folds)

The muscularized folds of mucous membrane that extend from the larynx (voice box) wall. The folds are enclosed in elastic vocal ligament and muscle that control the tension and rate of vibration of the cords as air passes through them.

Volume control

With many hearing aids you can change the volume with a simple wheel, buttons or a tap of the finger to change volume settings.


Waardenburg syndrome

A hereditary disorder that is characterized by hearing impairment, a white shock of hair and/or distinctive blue color to one or both eyes, and wide-set inner corners of the eyes. Balance problems are also associated with some types of Waardenburg syndrome.


For more  Glossary of Hearing Terms, go here.