This glossary provides a general reference for frequently used audiological terms that you may find on ATA’s website, within scientific literature, in medical reports or in conversations with your hearing health professional.
Acoustic Neuroma: Also called a schwannoma. A noncancerous (benign), often slow-growing tumor on the acoustic nerve, which connects the ear to the brain. This is a very rare cause of tinnitus.
Acoustic Reflex Test: A test that measures the contraction of the middle ear muscles in response to loud sounds.
Acoustic Startle Reflex: A subject’s startle reflex or quick response to a loud noise.
Acoustic Trauma: Damage to the sensorineural system (inner ear) caused by a single loud blast or explosion, or prolonged exposure to loud such conditions.
Agonist: A drug that can combine with receptors in the nervous system, to effect a particular action.
Aminoglycoside: A class of antibiotics used to treat serious bacterial infections. This class of drugs is generally very ototoxic.
Amplitude: The strength or volume of an acoustic or electromagnetic signal, usually measured in decibels.
Amplitude Modulation: To change the decibel strength or volume of an acoustic or electromagnetic signal.
Amygdala: A limbic system structure involved in many of our emotions and motivations, particularly those that are related to survival.
Angiogram: An X-ray photograph of blood or lymph vessels.
Animal Model of Tinnitus: See Behavioral Model of Tinnitus.
Anodal: A positively charged electrode.
Antagonist: A drug that blocks or works against the action of another drug, or prevents a particular body action from taking place.
Arteriovenous Fistula: An abnormal connection between vessels associated with disturbance of blood flow.
Attenuation: Reducing noise level through the used of hearing protection or other means (e.g. moving away from from source.)
Audiogram: A subjective test that measures the patient’s hearing across multiple frequencies (measured in Hertz) and volumes (measured in decibels)
Audiologist: A healthcare professional trained to evaluate hearing loss and related disorders, (including tinnitus,) and to rehabilitate people with hearing loss and related disorders. Audiologists use 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 loss. Most audiologists have advanced doctorate degrees.
Audiometer: The electronic instrument used by the audiologist for measuring the threshold of hearing.
Audiometric Evaluation (AE): Term used to describe a diagnostic hearing test, performed by a licensed audiologist. An audiometric evaluation allows the audiologist to determine the type and degree of your hearing loss, and it tells the audiologist how well or how poorly you understand speech. The AE also includes a thorough case history (interview) as well as visual inspection of the ear canals and eardrum.
Auditory: Of or relating to hearing, the organs of hearing, or the sense of hearing.
Auditory Brainstem Response (ABR) Test: Also called Brainstem Evoked Response (BSER), Brainstem Auditory Evoked Response (BAER), and Auditory Evoked Response (AER). This test objectively measures hearing by recording electrical activity in the brain when sound occurs. It is used for newborn babies, infants, and young children who cannot respond reliably using standard procedures such as visual reinforcement audiometry, play audiometry, or picture identification.
Auditory Cortex: The highest level of the brain that receives inputs from the lower auditory regions of the brain, including the inner ear, and interprets the neural activity from these lower regions into sound.
Auditory Deafferentation: The interruption of sensory nerve impulses caused by damaged or injured sensory nerve fibers.
Auditory Nerve: The nerve that connects the cochlea (inner ear) to the cochlear nuclei within the brain. It consists of the cochlear and vestibular nerves, and is responsible for hearing and balance. Also known as the eighth cranial nerve.
Auditory Neuropathy: A hearing disorder in which sound enters the inner ear normally but the transmission of signals from the inner ear to the brain is impaired. It can affect people of all ages, from infancy through adulthood. The number of people affected by auditory neuropathy is not known, but the condition affects a relatively small percentage of people who are deaf or hearing-impaired.
Auditory Perception: The ability to identify, interpret, and attach meaning to sound.
Auditory Prosthesis: Device that substitutes or enhances the ability to hear.
Auditory System: The outer, middle, and inner ear, and the parts of the brain related to hearing.
Aural: Having to do with the ear or hearing.
Barotrauma: Injury to the middle ear caused by a reduction or change of air or water pressure.
Basal Measures: Measurements of vital organism activities, such as heartbeat and respiration.
Baseline Hearing Test: A baseline hearing test will typically involves a variety of tests, including: Pure Tone Audiometry, Speech Audiometry, Tympanometry, Acoustic Reflex Testing and Otoacoustic Emissions Testing. The results will be used to make future comparisons about change of hearing abilities over time. After a baseline is complete, the audiologist will make recommendations for further care.
Behavioral Model of Tinnitus: An animal, usually a rodent, that has been trained to demonstrate a recognizable behavior when it is hearing tinnitus. A tinnitus animal model helps scientists learn where tinnitus comes from, how it progresses, or how well a treatment works. Also known as Animal Model of Tinnitus.
Bilateral Hearing Loss: Hearing loss in both ears.
Bilateral Tinnitus: Tinnitus that affects both the right and left ears.
Bimodal: Involving or having two different modes or means of delivery.
Binaural: Perception of sound with both ears; transmission of sound from two sources.
Biofeedback: A method of relaxation that allows the patient to control his or her own heart rate, blood pressure, breathing, and muscle tension. Often used as an adjunct to other tinnitus treatments.
Brain Stem: The stem-like part of the brain connected to the spinal cord, which manages messages between the brain and the rest of the body.
Bruits: Unusual sound that blood makes when it rushes past an obstruction (called turbulent flow) in an artery when the sound is listened to with the bell portion of a stethoscope.
Cathodal: A negatively charged electrode.
Central Auditory Processing Disorder: Inability to differentiate, recognize, or understand sounds; hearing and intelligence are normal.
Central Lesion: Any visible local abnormality of the tissues of the brain or spinal cord (i.e. the central nervous system).
Central Nervous System: Part of the nervous system consisting of the brain and spinal cord, that coordinates activity throughout the body.
Cerebral Cortex: Outermost layer of the brain, largely responsible for higher brain functions, including sensation, voluntary muscle movement, thought and reasoning and memory.
Cerumen: Medical term for ear wax, a yellow secretion from glands in the outer ear that keeps the skin of the ear dry and protected from infection.
Ceruminosis: Excessive ear wax.
Cholesteatoma: A non-cancerous tumor in the middle ear largely composed of skin cells.
Clinical Masking: A product that produces a broad bandwidth of sound (usually 3,000 to 12,000 Hz) that encompasses the frequency and volume of the tinnitus. The neutral masker sound is generally a more acceptable sound than the tinnitus. Success with masking is based in the observed phenomenon that non-threatening external sound can bring relief to the tinnitus ear.
Clonazepam: A drug in the benzodiazepine family, which has anxiolytic, anticonvulsant, muscle relaxant, and hypnotic properties.
Cochlea: The spiral-shaped organ in the inner ear that contains hair cells.
Cochlear Implant: Medical device that bypasses damaged structures in the inner ear and directly stimulates the auditory nerve, allowing some deaf individuals to hear and interpret sounds and speech.
Cochlear Lesions: Pathological or traumatic discontinuity of the cochlea or loss of function of the cochlea.
Cochlear Nucleus: A collection of neurons in the brainstem that receive input from the cochlear nerve and carry sound information from the cochlea.
Cognition: Thinking skills that include perception, memory, awareness, reasoning, judgment, intellect, and imagination.
Cognitive Behavioral Therapy (CBT): Attempts to solve emotional, behavioral or thought disorders through a psychotherapeutic approach.
Conductive Hearing Impairment: Hearing loss caused by dysfunction of the outer or middle ear.
Contralateral: On the opposite side.
Cortical: Of or relating to a cortex in the brain.of or relating to a cortex in the brain.
Cortical Hubs: Complex network of fibers bundles, that are believed to play pivotal roles in the brain’s coordination of information and sensory processing.
Cortical Map Reorganization: The ability of neurons to regroup themselves after an event that changes their normal organization and/or operation.
Cortical Network: The system interacting neurons within the brain’s auditory cortex.
Cortical Synchronization: The rallying of groups of neurons in varying regions of the brain, to engage in coordinated activity.
Cross-Sectional Survey: A study in which a statistically significant sample of a population is used to estimate the relationship between the results of the study and the various characteristics of the population studied at a certain point in time.
Decibel (dB): A unit that measures the intensity or loudness of sound.
Decibel A-Weighted (dBA): A unit of noise measurement designed to approximate the response of the human ear to moderate sound pressure levels.
Decibel C-Weighted (dBC): A unit of noise measurement designed to approximate the response of the human ear to high sound pressure levels.
Diagnostic Hearing Services: A wide range of tests to help the clinician diagnose the patient. These tests can include: Pure Tone Audiometry, Speech Audiometry, Tympanometry, Acoustic Reflex Testing, Otoacoustic Emissions Testing
Dopamine: A chemical neurotransmitter produced by the brain. Dopamine is released by neurons to stimulate neighboring neurons to successfully pass impulses from one cell to the next through the central nervous system
Dorsal Cochlear Nucleus (DCN): One of the first “relay stations” between the cochlea and the brain. The DCN receives and processes nerve impulses from the ear and sends the processed signals to higher relay centers in the brain. When these impulses reach the auditory cortex, they are interpreted as sounds.
Dorsolateral Prefrontal Cortex (DLPFC): area of the brain that serves as the highest cortical area responsible for motor planning, organization, and regulation. It plays an important role in the integration of sensory and mnemonic information and the regulation of intellectual function and action. Also involved in working memory.
Dosimeter: Specialized sound level meter that measures noise exposure (in dBA) over time and integrates the total exposures so that the result is representative of the risk.
ENT: See Otolaryngologist
Ear Infection: Presence and growth of bacteria or viruses in the ear.
Earwax: Also known as cerumen. a yellow secretion from glands in the outer ear that keeps the skin of the ear dry and protected from infection.
Electroencephalogram/Electroencephalography (EEG): Test that measures and records electrical brain activity.
Epidural Region: The outermost part of the spinal cord.
Epidemiology/Epidemiological: Dealing with incidence, distribution and control of diseases.
Epidural Electrical Stimulation: Treatment involving implanted electrodes in the epidural region of the body.
Etiology: The cause or causes of a disease or abnormal condition; a branch of medical science dealing with the causes and origins of diseases.
Eustachian Tube: The air duct which connects the nasopharynx (back of the throat) with the middle ear; usually closed at one end, opens with yawning and swallowing; allows ventilation of the middle ear cavity and equalization of pressure on two sides of the eardrum.
Evoked Potential (EP): Measurement of the voltage produced by cells in the brain in response to sound.
Exchange Rate: Number of decibels that a noise level is increased when the exposure level has been doubled; a 3 dB exchange rate means that for each 3 dB increase in noise level, the exposure level has been doubled.
Free Radicals: An atom or molecule having at least one unpaired electron. Hair cells in your inner ears are particularly susceptible to damage by free radicals.
Frequency: Also known as pitch. The number of times a repetitive event occurs in a specified time period. In terms of sound, frequency refers to the cycles of full sound waves per second, measured in Hertz (Hz.)
Frontal Cortex: The front lobe of the brain, which contains most of the dopamine-sensitive neurons in the cerebral cortex. The dopamine system is associated with reward, attention, short-term memory tasks, planning, and motivation.
Functional Magnetic Resonance Imaging (fMRI): A medical test that records changes in brain activity by measuring associated changes in blood flow through different structures of the brain Unlike an MRI, which can only record the physical appearance of the brain, an fMRI records brain activity.
GABA Receptor: An ionotropic receptor of gamma-aminobutyric acid (a neurotransmitter in the brain).
GABAergic: Transmitting or secreting γ-aminobutyric acid, an inhibitory neurotransmitter in the brain that contributes to motor control, vision and other cortical functions. This helps induce relaxation, sleep and balances the brain by inhibiting over-excitation.
Gamma-Aminobutyric Acid (GABA): An inhibitory chemical neurotransmitter in the brain that contributes to motor control, vision and other cortical functions. It also helps induce relaxation and sleep and balances the brain by inhibiting over-excitation.
Gap Detection: Introduction of two stimuli (e.g., tones, clicks, broad band noise) of some duration with a variable gap between them.
Gap Detection Threshold: The ability for a patient to determine when there is a break (gap) in between two stimulus sounds. The threshold is the shortest amount of time between two sounds where a patient can distinguish the silence between the sounds.
Gaze-Evoked Tinnitus: A rare form of tinnitus that may arise after vestibular schwannoma removal that typically arises in the deaf ear on the side of surgery and can be modulated by peripheral eye movement.
Global Networks: Regions of the brain involved in auditory and non-auditory processing. The core network structures include the prefrontal cortex, orbitofrontal cortex and parieto-occipital region.
Glutamate: A vital neurotransmitter in communication between nerve cells, making them more likely to send on a signal; excessive glutamate production, caused by stressed, loud noise or ototoxic chemicals, is thought to play a key role in the development of tinnitus.
Habituation: Process by which repeated and harmless stimulation leads to less and less perception and reaction. Habituation is one of the primary elements in many tinnitus management regimens.
Habituation-Based Therapy: Any number of therapies, like Tinnitus Retraining Therapy, directed at using habituation to minimize the troubling effects of tinnitus and/or hyperacusis.
Hair Cells: Tiny sensory cells that convert sound vibrations into neural activity. These sensory hair cells are arranged in orderly rows inside the cochlea. Hair cells have hair-like stereocilia that stick out of the top, giving them their name.
Hearing: 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 Disorder: Disruption in the normal hearing process that may occur in outer, middle, or inner ear, whereby sound waves are not converted to electrical signals and nerve impulses are not transmitted to the brain to be interpreted.
Hearing Handicap Inventory for the Elderly (HHIE): A self-assessment tool is designed to assess the effects of hearing impairment on the emotional and social adjustment of elderly people.
Hearing Loss Prevention Act (1983): Promulgated by the Occupational Safety and Health Administration (OSHA), this piece of legislation sets a maximum allowable noise dose to protect a large percentage of people; however, these regulations set only minimum safety standards, only apply to the occupational setting, and, per OSHA, admittedly do not protect a significant subset of the population.
Hearing Protection Device (HPD): Collectively, devices that are worn on, over, or in the ears to attenuate sound in an effort to minimize its potential damaging effect on hearing.
Hearing Threshold: The quietest sound audible 50% of the time when a person in undergoing a hearing test.
Hereditary Hearing Impairment: Hearing loss passed down through generations of a family.
Hertz (Hz): The unit measurement of frequency (pitch) of sound. Hertz quantifies the number of cycles of a sound wave in one second (cycles per second.) High-pitched sounds, such as a police whistle, have a high frequency with thousands of cycles per second. Low-pitched sounds, such as far away thunder, have a low frequency with only a few cycles per second.
Heterodyning: To combine (a radio-frequency wave) with a locally generated wave of different frequency in order to produce a new frequency equal to the sum or difference of the two.
Hippocampal Pyramidal Neurons: Multipolar sensory neurons located in the hippocampus region of the brain.
Hippocampus: An area deep in the forebrain that helps regulate emotion and memory.
Homeostatic: The ability of a system to regulate its internal environment and remain stable.
Hyperactivity: An abnormal increase in brain activity.
Hyperacusis: Abnormally reduced tolerance to sound; a symptom where sound that is not especially loud, and not bothersome to other people, seems overwhelming, intense or even painful.
Hyper Monitoring: The discrepancy that exists between how loud a patient subjectively perceives their tinnitus and how loud it is objectively measured.
Hypothesis: A tentative statement that proposes a possible explanation to some phenomenon or event. Hypotheses form the baseline assumptions against which researchers gather evidence to support or reject.
Inferior Colliculus (IC): A midbrain structure that serves as the brain’s principal auditory center, receiving sound signals the ears.
Inhibition: Opposing or restraining the excitation of neurons or their target excitable cells.
Inner Ear: Part of the ear that contains both the organ of hearing (the cochlea) and the organ of balance (the labyrinth.)
Intracranial Hypertension: A condition where the cerebrospinal fluid (CSF) inside the skull reaches elevated levels.
Ipsilateral: Located on or affecting the same side.
Kilohertz (kHz): One thousand hertz or one thousand cycles per second (sound processing).
Labyrinth: A complex system of chambers and passageways of the inner ear, which includes both the hearing and balance portions of the inner ear.
Labyrinthine Hydrops: Excessive fluid in the labyrinth (organ of balance). This condition can cause pressure or fullness in the ears, hearing loss, dizziness, and loss of balance.
Labyrinthitis: An inflammation of the labyrinth. It can result in hearing loss/or balance problems.
Lesion: A region in an organ or tissue that has suffered damage.
Limbic System: A system of nerves, structures and networks within the brain that controls emotional processing, long-term memory, motivation and drive.
Localization: Identification of the location of a sound source.
Loudness: The perception or impression of the strength of a sound without reference to any physical measuring tool such as a sound level meter.
Magnetoencephalography (MEG): A test that measures the shifting magnetic fields in the brain, which are generated by the brain’s natural electrical currents
Masker: Sound source that interferes with the perception of another sound.
Masking: Interfering with the perception of one sound by another or the specific level of volume at which one sound can makes the other inaudible. In tinnitus management, masking involves the use of an external noise to cover the perceived sound of tinnitus.
Mastoid: The back portion of the temporal bone that contains the inner ear.
Melatonin: A hormone secreted by the pineal gland that assists in the initiation of sleep.
Ménière's Disease: Also known as endolymphatic hydrops. 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.
Microvascular Decompression: A surgical procedure that relieves abnormal compression of a cranial nerve.
Middle Ear: The portion of the ear lying immediately behind the eardrum and containing three tiny bones- malleus, incus and stapes. This area conducts sound from the eardrum to the inner ear.
Mild to Profound Hearing Loss: Generally, the degree of hearing loss is described using one of five categories: Mild (average from 25-40 dB HL); Moderate (average from 40-55 dB HL); Moderate/Severe (average from 55-70 dB HL); Severe (average from 70-90 HL); Profound (average greater than 90 dB HL).
Milliamperes: One thousandth of an ampere, a measure for small electric currents.
Misophonia: An aversion to sound.
MRI (Magnetic Resonance Imaging): Using magnetic fields and radio waves, an MRI provides a visual image of an individual brain’s anatomical structure
Multidisciplinary Approach: Composed of or combining several usually separate branches of learning or fields of expertise, specialized subjects or skills.
Musical Tinnitus: Also known as Musical Ear Syndrome. The perception of music or singing when no external noise is present. Musical tinnitus is very rare.
Myelin Sheath: The insulation surrounding nerve bundles.
Neural: Of or relating to a nerve, neuron or the nervous system.
Neural Correlate: Any bodily component, such as an electro-neuro-biological state or the state assumed by some biophysical subsystem of the brain, whose presence necessarily and regularly correlates with such a specific content of experience.
Neural Networks: Biological neurons that are connected or functionally related in a nervous system that often perform a specific physiological function.
Neuroplastic/Neuroplasticity: The ability of neurons in the brain to reorganize or change based on new conditions (such as hearing loss that generates tinnitus) or environmental stimulation (like sound therapy leading to habituation).
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.
Neuro Auditory Cortex: The region of the brain responsible for processing auditory (sound) information.
Neuroauditive Cortex Reprogramming: A therapy utilizing sound to reduce the perception of tinnitus.
Neurofeedback (NFB): Also referred to as neuropathy, neurobiofeedback or EEG Biofeedback. Type of feedback that uses real-time displays of electroencephalography to illustrate brain activity. Sensors placed on the scalp measure activity, which is displayed using video images or sound.
Neuroimagery: Various visualization techniques (PET, fMRI and MEG) used to either directly or indirectly image the structure and function of the brain.
Neuron: A nerve cell that transmits sensory data throughout the brain via electrical and chemical signals. There are nearly 100 billion neurons in the human brain. Neurons specialize to serve different general functions (ex: hearing) and to process specific stimuli (ex: sound).
Neuronal: Or or related to neurons that process and transmit information by electrochemical signaling.
Neuronal Degeneration: Progressive loss of structure or function of neurons, including the death of neurons in the brain.
Neuroticism: Fundamental personality trait in the study of psychology that includes tendencies toward negative emotional states, such as anxiety, anger, guilt and depression when faced with potentially stressful situations.
Neurotoxicity: Property of a natural or artificial substance that damages the nervous system.
Neurotransmitters: Chemicals in the brain which allow the transmission of signals from one neuron to the next across synapses.
NMDA Receptor Antagonist: A class of anesthetics that work to inhibit the action of the NMDA (an amino acid derivative that mimics the action of glutamate) receptors in the brain.
Noise: Sound with no particular information; in contrast to a signal such as speech or music, noise has random phase.
Noise Control Act (1972): A federal law that states that U.S. citizens are not to be subjected to noises that jeopardize health and well-being.
Noise-Induced Hearing Loss (NIHL): Hearing loss caused by exposure to harmful sounds, either very loud impulse sound(s) or repeated long-term exposure to sounds in excess of 85 dBA. NIHL is often characterized by decreased hearing sensitivity, tinnitus and/or hyperacusis.
Nucleus Accumbens: A collection of neurons within the subcortical part of the forebrain thought to play an important role in reward, pleasure, addiction, and the placebo effect.
Nystagmus: Abnormal, rapid, rhythmic, involuntary, alternating movements of the eyeball.
Objective Tinnitus: Head or ear noises that are audible to other people, as well as the patient. These sounds are usually produced by internal functions in the body’s circulatory (blood flow) and somatic (musculo-skeletal movement) systems. Objective tinnitus is very rare, representing less than 1% of total tinnitus cases.
Occipital: Of, relating to or located within or near the occiput (back of the head) or the occipital bone.
Occlusion: The “blocked” physical and sound sensation that results from having a hearing aid or earmold in the ear. The occlusion effect often makes patients perceive that their own voice with a deeper pitch, less clarity and/or with an echo.
Occupational Safety and Health Administration (OSHA): An agency of the U.S. government under the Department of Labor with the responsibility of ensuring safety at work and a healthful work environment.
Otic: Relating to or near the ear.
Otitis: A general inflammation of the ear.
Otitis Externa: Inflammation of the external ear canal usually caused by an infection. Also called “swimmer’s ear.”
Otitis Media: Inflammation of the middle ear or ear drum.
Otorrhea: A purulent discharge from the ear; ear drainage.
Otoacoustic Emissions: Low-intensity sounds produced by the inner ear that can be quickly measured with a sensitive microphone placed in the ear canal.
Otolaryngologist: A physician/surgeon who specializes in diseases of the ears, nose, throat, and head and neck. They are commonly referred to as ENT physicians.
Otologist: A physician/surgeon who specializes in diseases of the ear.
Otorrhagia: Bleeding from the ear canal; ear hemorrhage.
Otosclerosis: An inherited dominant genetic condition that causes abnormal spongy bone growth on the tiny bones in the middle ear and surrounding bone.
Ototoxic: Drugs that are injurious or harmful to the ear- especially to the organs or nerves of the ear concerned with hearing and balance.
Outer Ear: External portion of the ear, consisting of the pinna, or auricle, and the ear canal.
Pathogenesis: The manner of a development of a disease or condition.
Pathophysiology: The study of the changes of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from an abnormal syndrome.
Perforated Eardrum: Also known as tympanic membrane perforation. An eardrum that has ruptured or has a hole in it.
Permanent Threshold Shift (PTS): A permanent decline in hearing following overexposure to noise. PTS usually occurs after repeated exposures to loud noise, but can also occur after only one traumatic exposure to noise. Most workers experience a Temporary Threshold Shift in hearing prior to a Permanent Threshold Shift. But because of individual variations in tolerance to noise, there is no way to predict when a shift in hearing will become permanent. Therefore, hearing protection is critical for all loud noise exposures.
Pitch: See Frequency
Placebo: Also referred to as a sham. A treatment used in a scientific study as a control, usually omitting some or all key therapeutic elements of the treatment being studied.
Plasticity: The ability of the synapse (connection) between two neurons to change in strength.
Polychoric Correlations: Multiple measures of associations (strength) of the relationship between two variables.
Prefrontal Cortex: The anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas.
Presbycusis: Loss of hearing that gradually occurs because of changes in the inner or middle ear in individuals as they grow older.
Propagation: A phenomenon by which the motion of the original vibrating surface "travels" as a wave in all directions provided there is a medium.
Psychoacoustics: A branch of science dealing with subjective human perceptions of sounds.
Psychoacoustic Test: Measures the subjective human perception of sound (tinnitus).
Psychophysical: Relating to the relationships between physical stimuli and sensory response.
Pulsatile Tinnitus: The perception of pulsing sounds, often in-beat with the patient’s heartbeat.
Pure Tone: A sound wave having only one frequency of vibration.
Pure-Tone Audiogram: An audiogram based on listening to pure tones as opposed to listening to speech.
Pure-Tone Thresholds: The measurement of an individual's hearing sensitivity for calibrated pure tones.
Randomized, Double-Blind Study: A clinical study where research subjects are assigned at random to one of two or more groups. Group interventions can include medication/practice being studied, another medication/practice, placebo (“sugar pill”) or no intervention. Double-blind means neither investigators nor participants know what each group receives.
Recruitment: An abnormally greater increase in loudness in response to increased sound intensity as compared with a normal ear.
Repetitive Transcranial Magnetic Stimulation (rTMS): Noninvasive method that sends tightly focused magnetic pulses to stimulate brain nerve cells. rTMS is currently being studied as a treatment tool for various conditions, such as tinnitus, migraines, Parkinson’s disease and intractable depression.
Residual Inhibition Testing: Testing for the temporary suppression and/or disappearance of tinnitus following a period of masking.
Reverberation: Prolongation of sound by multiple reflections after the original sound is removed.
Round Window: The membrane separating the middle ear and inner ear.
Sensorineural Hearing Loss: Hearing loss caused by damage to the sensory cells and/or nerve fibers of the inner ear.
Sensory Cortex: A region of the cerebral cortex concerned with receiving and interpreting sensory information from various parts of the body.
Sham: See Placebo
Somatic Modulation: Movement of the jaw, head or neck that causes the loudness and/or frequency of one’s tinnitus to fluctuate.
Somatic Tinnitus: A type of tinnitus in which the perceived sound are produce by musculo-skeletal movement within the body.
Somatosensory: Neural activity caused by activation of sensory receptors on the body (e.g., through touch, vibrations, movements of muscles). For some people, somatosensory activity (e.g. movements or touch to the arm, neck or face) can cause the perception of tinnitus to change.
Somatosensory Cortex: Area of the brain which processes input from the various systems in the body sensitive to touch.
Sound: Particle vibrations in an elastic medium.
Sound Generator: A device that plays quiet, soothing sounds to reduce the awareness of tinnitus. Sound generators can be standalone devices, or be incorporated into other hearing instruments.
Sound Level Meter: Device that measures sound levels in decibels.
Sound Power: Acoustic power output of a sound source measured in watts.
Sound Therapy: A type of tinnitus management that introduces sound into the auditory cortex of the brain for the purpose of refocusing the brain’s attention away from the tinnitus. Most sound therapies introduce sound at a pleasant level at the “mixing point” between the loudness of the tinnitus and a low noise floor.
Startle (Reflex): Response of mind and body to a sudden unexpected stimulus, e.g., flash of light, loud noise or quick movement near the face.
Standard Threshold Shift (STS): A significant change in hearing thresholds, defined by OSHA as an average decline of 10 dB or more at 2000, 3000, and 4000 Hz in a given ear, relative to a baseline audiogram.
Statistical Significance: A change caused by the treatment that is greater than the change that could be expected based on chance.
Subjective Tinnitus: Head or ear noises that are perceivable only to the specific patient. Subjective tinnitus is usually traceable to auditory and neurological reactions to hearing loss, but can also be caused by an array of other catalysts. More than 99% of all tinnitus reported tinnitus cases are of the subjective variety.
Sudden Sensorineural Hearing Loss (SSHL): A rapid loss of hearing. SSHL can happen to a person all at once or over a period of up to 3 days.
Synapse: A structure in the nervous system that permits a neuron to pass an electrical or chemical signal to another cell.
Synaptic Plasticity: The ability of the synapse (connection) between two neurons to change in strength.
Syndromic Hearing Impairment: Hearing loss or deafness that, along with other characteristics, is inherited or passed down through generations of a family.
Temporal Cortex: Each of the paired lobes of the brain lying beneath the temples, including areas concerned with the understanding of speech.
Temporal Masking: Masking produced by a noise that occurs either just before or after the signal occurs.
Temporary Threshold Shift (TTS): Initial overexposures to noise cause a temporary decline in hearing, which may last for a few minutes or hours. A person with a Temporary Threshold Shift will perceive incoming sound as being muffled, or not as sharp; but once the ear has rested for some time, hearing recovers to normal levels. Physiologists believe the receptor cells in the ear fatigue with loud noise exposures, and require several hours of relative quiet to return to their normal state. Repeated overexposures to loud noise, however, cause permanent damage, from which the ear cannot recover [see Permanent Threshold Shift].
Temporoparietal: Affecting the temporal and parietal lobes of the cerebral hemisphere.
Temporoparietal Cortex: A region of the brain known to be involved in speech perception.
Thalamus: A symmetrical structure within the brain, situated between the cerebral cortex and midbrain, that relays sensory and motor signals to the cerebral cortex, along with the regulation of consciousness, sleep and alertness.
Threshold: Quietest sound audible 50% of the time.
Tinnitus: The perception of sound in the ears or head where no external source is present.
Tinnitus Handicap Inventory (THI): A self-reported test utilized to assess a person’s tinnitus-related handicap and to report treatment outcomes.
Tinnitus Handicap Questionnaire (THQ): A self-reported test used to evaluate the emotional aspect of tinnitus, as well as problems that are associated with concentration, hearing, and sleep due to tinnitus.
Tinnitus Pathophysiology: The study of the changes or normal mechanical, physical and biochemical functions affected by tinnitus.
Tinnitus Pitch Matching: A test of physical tones that is matched to the sounds or tones that a person with tinnitus hears with the goal of quantifying tinnitus in terms of its possible frequency. It is used as a reference point for discussion for the clinician and patient.
Temporomandibular Joint Disorders (TMJ): A disharmony between the way the jaw joint works in its most unstrained position and the way the teeth occlude during those movements.
Tonal Tinnitus: The perception of near-continuous sound (or overlapping sounds,) with well-defined frequencies. The perceived volume of the tinnitus often fluctuates.
Tonotopic Map: The orderly projection of inputs originating from the cochlea to sensory areas in the brain, such that neighboring neurons in the target regions respond to progressively higher frequencies.
Transcranial Direct Current Stimulation (tDCS): The application of weak electrical currents to modulate the activity of neurons in the brain.
Transcranial Magnetic Stimulation (TMS): A noninvasive method used to excite brain neurons. Weak electric currents are induced in the tissue by rapidly changing magnetic fields (electromagnetic induction) to study the functionality of the circuitry and connectivity of the brain.
Trigeminal Ganglion: A sensory structure containing a number of nerve cell bodies, typically linked by synapses of the trigeminal nerve.
Tympanogram: The graph that results from tympanometry, describing the acoustic evaluation of the outer and middle ear's ability to accept and conduct sound.
Tympanometry: The measurement of the outer and middle ear's ability to accept and conduct sound.
Ultrasonic Tinnitus Treatment: Focuses on high-frequency auditory stimulation that occurs via bone conduction.
Unilateral Hearing Loss: Hearing loss in one ear, either the left or right side.
Unilateral Tinnitus: Tinnitus perception occurring in one ear, either the left or right side.
Vagus Nerve: A nerve in the neck that conveys sensory information about the state of the body’s organs to the central nervous system.
Vagus Nerve Stimulation (VNS): Use of an implanted stimulator that sends electrical impulses to the vagus nerve in the neck. VNS is used to treat intractable depression and is being studied as a possible remedy to some forms of tinnitus.
Vascular: Relating to or consisting of vessels, especially those that carry blood.
Ventromedial Prefrontal Cortex: A part of the brain implicated in the processing of risk and fear, and in decision making.
Vertigo: The illusion of movement, often accompanied by feelings of imbalance and/or nausea. Vertigo is a common result of damage to the balance system of the inner ear.
Vestibular Disorder: Disorders that affect one’s balance.
Vestibular Schwannoma: See Acoustic Neuroma.
Vestibular System: The portion of the inner ear and the central nervous system involved with the sense of balance. This system controls your equilibrium (balance) and stabilizes your eyes in space. It works together with your brain to sense, maintain and regain your balance and a sense of where your body and its parts are positioned. Movement is regulated here.
Vestibulocochlear Nerve: A sensory nerve responsible for transmitting sound and equilibrium information from the inner ear to the brain; also known as the 8th nerve.
Visual Analog Scale (VAS): A measurement instrument used for subjective characteristics or attitudes that cannot be directly measured.
Voxel-based Morphometry: A neuroimaging analysis technique that allows investigation of focal differences in brain anatomy.
Washout Period: A chance for the body to clear itself of any medication.