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Acoustic reflex test

A test to determine if the ear’s natural and involuntary reflex to lower the volume of loud sounds is working properly.

Alerting devices

Devices that use loud sounds or visual signals, such as a blinking light, to notify you that the doorbell or telephone is ringing or that an alarm is going off.


One of the three small bones, called ossicles, in the middle ear. The anvil is also known as the incus.

Assistive listening devices

Devices that help reduce background noise and amplify the sounds you want to hear. They are also known as hearing assistive technology systems, or HATS.


A hearing health professional who treats people with hearing, balance, and related disorders.

Audiometry exam

A test to determine your ability to hear sounds based on intensity and tone. It can reveal the type and amount of hearing loss you are experiencing.

Auditory brainstem response (ABR)

A test that assesses the functionality of the auditory neural pathway.

Auditory injury

An injury that can cause damage to your hearing.

Auditory injury disability ratings

A rating assigned by the VA reflecting the degree of disability caused by hearing loss or tinnitus. Ratings range from zero to 100 percent.

Auditory neural pathway

The auditory nerve carries impulses from the cochlea to a relay station in the mid-brain. The nerve impulses are then carried to other brain pathways that end in the hearing part of the brain.

Auditory processing disorder (APD)

A complex problem affecting the way the central nervous system recognizes and interprets sound, most notably the sounds composing speech. A person with APD doesn’t process the information they hear because their ears and brain don't fully coordinate the information.

Auditory steady state response (ASSR)

A test that objectively identifies the brain’s response to different pitches and volumes.

Auditory system

The sensory system for hearing.


A portion of the outer ear that is made mostly of cartilage. It is also called the pinna.

Autoimmune inner ear disease

The name used to describe a variety of disorders in which the ear is the sole target of an inappropriate attack by the immune system.

Balance disorder

A condition in which your balance is impaired. It may be difficult to maintain orientation, which can be experienced as a number of different symptoms. Inner ear dizziness, or vertigo, is a common symptom, and it can make you feel like the room is spinning.

Basilar membrane

An elastic membrane that runs from the beginning to the end of the cochlea, splitting it into an upper and lower part.

Benign paroxysmal positional vertigo (BPPV)

A condition in which a person experiences an intense sensation of spinning whenever they change their head position. It is one of the most common balance disorders.

Bone conduction devices

Hearing devices that are implanted or worn to directly transmit sound vibrations to the inner ear, bypassing the ear canal and the middle ear, and stimulating the inner ear through the skull. They are also referred to as bone-anchored hearing aids, bone-conduction simulators, or bone-conductor implants.



Hair cells in the inner ear.


A portion of the inner ear also known as the organ of hearing. It is shaped much like a snail’s shell and has small hair cells called cilia that are bathed in fluid.

Cochlear implant

An electronic device surgically implanted in the inner ear that provides partial hearing to patients with severe-to-profound bilateral hearing loss.


Mental processing, such as decision making and reasoning.

Cognitive therapy

A type of counseling that is based on treating a patient's emotional reaction to tinnitus, or ringing in the ears, and improving their ability to cope with it.

Conductive hearing loss

Hearing loss that occurs as a result of a problem in the outer or middle ear, and is usually perceived as a reduction in sound level or an inability to hear faint sounds.

Cooperative Research and Development Agreement (CRADA)

A written agreement between a non-federal entity and a government agency to work together on a project.

CT scan

Computed tomography (CT) uses computer-processed x-rays to produce virtual “slices” of specific areas of the scanned object or portion of the body.


The unit measurement of sound, often abbreviated as dB.


Ear canal

A narrow passageway, approximately one inch long, that connects the pinna to the eardrum. The ear canal serves as a natural resonator, making sounds louder, deeper, and clearer.

Ear drum

A thin membrane that separates the middle ear from the inner part of the external auditory canal. It vibrates in response to sound energy and transmits the resulting mechanical vibrations to the structures of the middle ear. It is also called the tympanic membrane.

Ear plug

A type of hearing protection device (HPD). Simple foam ear plugs can reduce the amount of noise entering the ear. They are the most commonly available type of HPD.

Eustachian tube

A pressure-equalizing valve that drains any fluid, which collects in the middle ear, into the back of the throat. The tube opens and closes to equalize air pressure within the middle ear, making it easier for sound to travel to the inner ear.


A property of sound that determines pitch.



One of the three small bones, called ossicles, in the middle ear. The hammer is also known as the malleus.

Health Information Portability and Accountability (HIPAA) Act

Regulations that protect the privacy of individually identifiable health information.

Hearing aid

An electronic device usually worn in or behind the ear that amplifies sound.

Hearing conservation program

A strategy and program that helps protect and conserve peoples’ hearing.

Hearing evaluation

Tests performed by an otolaryngologist or audiologist to determine if you have hearing loss.

Hearing loss

See conductive hearing loss, mild hearing loss, mixed hearing loss, moderate hearing loss, profound hearing loss, sensorineural hearing loss, and severe hearing loss.

Hearing protection device (HPD)

A wearable device that protects your auditory system against potentially damaging noise levels. The most common HPDs are ear plugs, noise muffs, and noise attenuating helmets.

High frequency audiometric notch

A decrease in hearing sensitivity on an audiogram that is typically seen at 3-6000 Hz with some recovery at frequencies higher than where the notch occurs. This high frequency audiometric notch is typical of noise-induced hearing loss.

High frequency hearing impairment

The inability to hear high pitches.

Impulse noise

A sudden, loud sound, such as an explosion.


One of the three small bones, called ossicles, in the middle ear. The incus is also known as the anvil.

Induction loop system

A hearing assistive technology system that works with a hearing aid.

Infrared system

A hearing assistive technology system that uses infrared light waves to transmit sound from the TV. This sound is transmitted to your receiver, which you can adjust to your desired volume.

Inner ear

It has two major parts — the cochlea and the vestibular system. The cochlea houses the sound-analyzing cells, and the vestibular system houses the balance organs. The inner ear is one of three parts of the entire ear.



A maze-like structure in the inner ear, which is made of bone and soft tissue. It controls your sense of balance.


One of the three small bones, called ossicles, in the middle ear. The malleus is also known as the hammer.

Ménière’s disease

Ménière’s disease is a disorder of the inner ear that can cause episodes of spinning dizziness, or vertigo, that are associated with tinnitus, hearing loss, and ear pressure.

Middle ear

One of three parts of the ear. It is an air-filled chamber that contains three small bones called ossicles, which form a connection from the ear drum to the inner ear.

Middle ear implant (MEI)

These devices are implantable alternatives to hearing aids, and are used to treat people with sensorineural hearing.

Mild hearing loss

Hearing loss that makes it difficult to catch every word of a conversation if there’s background noise.

Mixed hearing loss

A combination of conductive and sensorineural hearing loss. There may be damage to the outer or middle ear, as well as in the inner ear or along the auditory nerve. Mixed hearing loss can be caused by a head injury, chronic infection, or an inherited disorder.

Moderate hearing loss

Hearing loss that may cause you to ask people to repeat themselves during one-to-one and telephone conversations.

MRI scan

A noninvasive diagnostic technique that produces computerized images of internal body tissues. It is based on nuclear magnetic resonance of atoms within the body stimulated by the application of radio waves.

Neuronal loss

Loss of nerve cells that transmit information through your body via electrical and chemical signals.


In the non-technical sense, any unwanted sound. Noise may be steady, either a pure tone or a combination of tones, or it may consist of one or more impulses. The term is usually applied to sounds having a complex character with numerous separate frequency components extending over a wide range of frequencies and that are not generated to convey meaning or information.

Noise attenuating helmet

A type of hearing protection device. It protects the wearer from hearing loss, crash impact, and eye injuries, and can also improve communication through use of a radio communication piece.

Noise-cancelling headphones or ear buds

Headphones or ear buds that block out background noise and allow for lower volume with a personal listening device.

Noise-induced hearing loss

Inner ear damage that results in hearing loss. It can be caused by repeated exposure to loud sounds over a period of time and/or one-time exposure to high-intensity noise.

Noise meter

A device that measures sound levels.

Noise muff

A type of hearing protection device (HPD). It consists of two tightly fitted ear cups that cover each ear entirely and block noise from entering the auditory system.

Noise toxicity

Too much sound or any unwanted sound that feels uncomfortable to you, whether it’s due to intensity, content, or duration. This type of sound can cause adverse health effects.

Objective tinnitus

A ringing in the ears your healthcare provider can hear with a stethoscope or sometimes by simply listening in close proximity to your ear. This kind of tinnitus is rare.

Occupational noise

Noise in the workplace.


Three small bones in the middle ear that are named the malleus (hammer), incus, (anvil), and stapes (stirrup). They are collectively referred to as the ossicular chain.

Otitis media

An infection of the middle ear, behind the ear drum.

Otoacoustic emission (OAE) test

A test that measures hair cell function in the inner ear.


A healthcare specialist who treats disorders of the ear, nose, and throat.

Otolithic organs

Two organs in the inner ear called the saccule and utricle.


Abnormal spongy bone growth that develops around the stapes (stirrup) in the middle ear and causes hearing loss.


An instrument used to examine your ear.

Ototoxic medications

Medications that may cause hearing loss, such as aspirin and ibuprofen.

Outer ear

One of three parts of the ear. It is the external portion of the ear that consists of skin and cartilage, called the auricle, or pinna, and the ear canal.


Personal amplifier

A hearing assistive technology system about the size of a cell phone that increases sound levels and reduces background noise for a listener. As with other assistive listening devices, the amplified sound can be picked up by a receiver that the listener is wearing, either as a headset or as ear buds.

Personal frequency modulation (FM) systems

Assistive listening devices that operate on special frequencies. The personal FM system consists of a transmitter microphone used by the speaker and a receiver used by the listener.

Personal listening device

A machine, such as an MP3 player, that allows you to listen to music, podcasts, and audio files.


A portion of the outer ear that is made mostly of cartilage. It is also called the auricle.

Poly-trauma patient

A person who has received multiple injuries, such as those with traumatic brain injury, who experience hearing loss and other visible or invisible injuries.

Post-traumatic stress disorder (PTSD)

A condition that can develop after someone witnesses or experiences a traumatic or terrifying event. Given the nature of combat and war zone environments, Service Members are at heightened risk for PTSD.

Profound hearing loss

Hearing loss that makes it impossible to hear other people speaking, even if they speak loudly or if hearing aids are used.

Progressive tinnitus management

A multi-facetted treatment regimen. It involves five levels of care, with each patient receiving an individualized course of care and condition management.

Pulsatile tinnitus

A rare type of tinnitus that sounds like a rhythmic pulsing in the ear, usually in time with your heartbeat. It is most often caused by fluid accumulation or infection in the middle ear space.

Pure-tone audiometry

The most common hearing test. It defines the faintest tones a person can hear at selected pitches, or frequencies, from low to high.

Recreational noise

Noise or sound that occurs during recreational activities, such as attending movies or sporting events.


Semicircular canals

An intricate system of loops and pouches in the labyrinth of the inner ear. They help maintain balance.

Sensorineural hearing loss

Hearing loss that often results from damage to the cilia, or hair cells, in the inner ear or to the nerve pathways from the inner ear to the brain. It is most commonly caused by exposure to loud noises or age-related changes to the nerves and sensory cells of the inner ear.

Severe hearing loss

Hearing loss that makes following a conversation difficult without a hearing aid.

Situational awareness

To know what’s going on around you and in your environment.

Sound therapy

A type of therapy also known as sound masking that uses sound to decrease the loudness or prominence of tinnitus, or ringing in the ears. Devices can be wearable, similar to a hearing aid, or non-wearable, such as tabletop sound machines or whirring fans.

Sound waves

Vibrations in the air pressure.

Speech audiometry

A test that determines your ability to hear and understand human speech.


One of the three small bones, called ossicles, in the middle ear. The stapes is also known as the stirrup.

Static acoustic impedance

A test that measures the physical volume of air in the ear canal to identify problems with the eardrum or ventilation tubes.


One of the three small bones, called ossicles, in the middle ear. The stirrup is also known as the stapes.

Subjective tinnitus

Ringing in the ears that only you can hear. Most people who experience tinnitus have subjective tinnitus.

Tactical communication and protective systems (TCAPS)

A wearable device that simultaneously protects hearing and enables auditory situational awareness.


Ringing in the ears. It is the perception of sound when no external sound is present. It’s not a condition in and of itself, but rather a symptom of some other problem in the auditory system.


A sound of definite pitch and vibration.

Traumatic brain injury (TBI)

A structural injury and/or physiological disruption of brain function as a result of external force, such as an explosion. Loss of consciousness, memory loss of events surrounding the injury, disorientation, and confusion are all indications of TBI. Hearing loss is often associated with TBI, either because the traumatic injury damages the inner ear or because there is damage to the part of the brain that processes sound.

Tympanic membrane

A thin membrane that separates the middle ear from the inner part of the external auditory canal. It vibrates in response to sound energy and transmits the resulting mechanical vibrations to the structures of the middle. It is also called the ear drum.


A chart showing the results of a tympanometry test, which is used to detect problems in the middle ear.


A test that detects fluid in the middle ear, eardrum perforation, and blockage in the ear canal.


Vestibular system

The system in your inner ear that consists of three semicircular canals, plus two organs called the utricle and the saccule. It helps you maintain your balance by sending messages to your brain about movement, direction, and steadiness.


Part of the inner ear that connects the cochlea to the labyrinth.

Quick Fact


The cochlea, vestibule, and labyrinth are part of the inner ear.

About Us

The Hearing Center of Excellence fosters and promotes the prevention, diagnosis, mitigation, treatment, rehabilitation and research of hearing loss and auditory injury. It supports the development, exchange and adoption of best practices, research, measures of effectiveness and clinical care guidelines to reduce the prevalence and cost of hearing loss and tinnitus among Warriors and Veterans. Read more

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