Acoustic feedback :Howl or whistle caused by the recirculation of acoustic output of an amplifying system. In a hearing aid the sound emanating from the receiver may reach (or feed back into) the microphone and be re-amplified until it builds up into a high-pitched whistle.
Acoustic nerves: The eighth cranial nerve, combining the nerves of hearing (cochlear) and balance (vestibular). Syn: auditory nerve, vestibulo-cochlear nerve.
Acoustic Reflex :The reflex contraction of the intra-aural muscles (tensor tympani and stapedius) in response to sound. Syn: intraaural reflex; cochlear reflex; auditory reflex.
AGCi (Automatic Gain Control) :Electronic automatic gain control for a hearing instrument. It sets the gain depending on the input level. AGCi is used for input signal compression (see Compression).
AGCo (Automatic Gain Control): : Electronic automatic gain control for a hearing instrument. It sets the gain depending on the output level. The AGCo is used to limit the output level.
Analog Hearing Instrument: Analog instruments can only process sound signals in analog format. Subsequent changes in functions are not possible. Digital programming of analog hearing instruments represents major progress in computer-supported, optimizing individual hearing instrument adjustment. It includes a series of controls (elements), while maintaining the instrument's small size. (See digitally programmable hearing instruments).
Audible range :The frequency range that can be perceived by the human ear. It is between 16 Hz and 20 000 Hz (depending on age).
Audiogram: Record of the threshold of sensitivity of hearing measured at several different (usually discrete) frequencies.
Audiologist: : : Person trained in audiology - a specialist in the problems of hearing and deafness - in America and Canada excluding the field of medicine.
Audiology: Study of hearing and hearing impairment. In Europe the term usually includes the study of the nature, causes, and treatment of diseases of the ear.
Audio Input :Contact at the hearing instrument that enables a connection cable or radio receiver to be connected. Used for interference-free reception of radio and TV, but also used for conferences, seminars, and training.
Audio shoe :A small device attached to a BTE hearing instrument used to connect FM receiver or other similar devices.
Automatic adaptive microphone:A directional microphone that is controlled by the digital circuit to recognize moving noise signal in the listening environment and change/adapt the polar to reduce their effects on the primary signal. The moving signals generally are coming from behind the wearer in the quadrant from 90 degrees to 270 degrees.
Automatic sound processing :Digital technology makes it possible to continually analyze and process incoming sound to best amplify speech while reducing unwanted noise. Soft sounds are given more amplification, while very loud sounds are given little or no amplification. Automatic sound processing makes hearing instruments simple to use and comfortable to wear and create hands-free operation with no need for external controls such as volume control wheels.
Behind-the-ear (BTE):aids fit comfortably behind the ear and are attached to a custom earmold. Many can be modified with connections to external sound sources such as auditory training equipment, infrared listening systems or television.
Binaural Classification: :A process in which the input signals from each hearing instrument of a binaural fitting are communicated via e2e wireless. They are combined to make a common decision on the optimal signal processing for that listening environment.
Binaural Coupling:The process that allows the operation of both hearing instruments from one control. The control (VC or push button) may reside on either instrument.
Binaural Hearing :(1) With both ears. (2.) Of or pertaining to sound transmission from two separate sound sources, which may vary acoustically relative to the listener, as in the wearing of two hearing instruments.
Binaural Hearing Instrument Fitting: A hearing instrument is used in each ear. Used because sound perception in both ears is required in order to differentiate between useful sounds and noise, concentrate on one person in a confusion of voices, or determine the direction of sounds in traffic.
Binaural Hearing System :An amplification system in which two hearing instruments are coupled to operate as one integrated unit. Functions such as volume control and memory (program) selection are synchronized between the two instruments for optimal performance of the system.
Cerumen :: Yellow or brown wax-like substance (earwax) secreted in the outer one-third of the external ear canal by the ceruminous glands. Adj: ceruminal, ceruminous.
CIC Completely-in the- Canal :A micro-miniature hearing aid that fits completely within the ear canal.
Cochlea :The cochlea is part of the inner ear. It is lined with thousands of microscopic hair cells. The vibrations of the stirrup set the colchlea fluid in motion, causing the hairs to bend from the waves of the moving fluid. The bending of these hairs sets off nerve impulses that are then passed through the right and left auditory nerves to the brain.
Cochlear Implant: A cochlear implant is an electronic instrument that restores partial hearing to the deaf. It is surgically implanted in the inner ear, and is activated by a device worn outside the ear. In contrast to a hearing aid, it does not make sound clearer or louder. Instead, the instrument bypasses damaged parts of the auditory system and directly stimulates the nerve of hearing, allowing individuals who are profoundly hearing impaired to receive sound.
Cochlear nerve: Branch of the eighth cranial (acoustic) nerve that arises in the cochlea and conveys sound stimuli to the brain.
Composite Noise: A sound stimulus generally composed of a large number of individual sinusoidal signals summed together for simultaneous presentation. The result is a "noise-like" stimulus with controlled spectral characteristics. Commonly used to mimic the spectrum of spoken speech.
Compression amplification: Method of limiting (or compressing) the amplification of loud sounds in comparison to weak sounds. When this type of circuit is used in a hearing aid or other amplifier, the wave form of a loud sound is less modified than when peak-clipping is used.
Conductive Hearing Loss: : This type of hearing loss is characterized by impaired sound conduction in the auditory canal, middle ear, or oval window. It represents approx. 5 - 10% of hearing impairments usually can be treated surgically.
Decibel: One-tenth of a Bel. Commonly noted as dB. A decibel is a unit of measurement used to express logarithmic ratios (to the base of 10) of intensity, power, pressure, etc.
Digitally Programmable Hearing Instrument: Instrument whose electroacoustic characteristics are set externally via computer. The primary advantage of programmable hearing instruments is that a range of electroacoustic parameters can be set, resulting in more accurate compensation for hearing loss. These hearing instruments are sometimes confused with or marketed as digital hearing instruments; actually, these instruments use analog signal processing (see fully digital hearing instruments).
Directional microphone: If one turns a microphone 360° in front of a sound source and draws a diagram of the voltage produced by the microphone, the result is a diagram indicating the directional characteristic of the microphone. An important feature of the directional microphone is that the diagram shows greater sensitivity (higher voltage) in one direction. Depending on the design, type, and placement of the directional microphone (anywhere in the sound field or positioned on the head), various curve shapes or characteristics are produced for the different areas of use.
Discomfort Threshold: Also called discomfort limit, indicates the sound pressure level at which sound becomes uncomfortably loud; for persons with normal hearing, this is 110 dB SPL. Loudness recruitment refers to hearing-impaired persons whose discomfort threshold is around the same range (+/ - 10 dB).
DSL [i /o] (Desired Sensation Level): Adaptive formula developed especially for children by a research group at the University of Western Ontario, under the direction of Dr. Richard C. Seewald. It considers the perception of loudness as follows: quiet signals are quiet, but are still perceived to be quiet. Medium-volume signals are perceived as comfortable and loud signals are considered loud, but not uncomfortable.
Ear (auris): Organ of hearing and balance that is divided into: 1. The external ear includes the sound-collecting visible portion (auricle or pinna), the outer ear canal (external auditory meatus), and the outer surface of the eardrum (tympanum). 2. The middle ear includes the inner surface of the eardrum, the ossicular chain (hammer, anvil, and stirrup - or malleus, incus, and stapes), the eustachian tube, and the outer surface of the oval and round windows (fenestrae). 3. The inner ear includes the vestibule, the semi-circular canals, the inner surface of the oval and round windows, and the cochlea.
Earache Ear pain: Any ache or pain arising in the ear. Technically it may be called otalgia or otodynia.
Conductive Hearing Loss: : This type of hearing loss is characterized by impaired sound conduction in the auditory canal, middle ear, or oval window. It represents approx. 5 - 10% of hearing impairments usually can be treated surgically.
Eardrum:The eardrum (or tympanic membrane) stretches across the inner end of the external ear canal and forms the outer boundary of the middle ear. It reacts to sound waves and starts the ossicular chain moving.
Ear specialist:Commonly accepted name for a medical ear specialist is otologist. He or she may also be known as an aural surgeon aurist. Other medical specialists especially interested in ears are variously known as otolaryngologists or otorhinolaryngologists - (oto) ear, (rhino) nose, (laryngo) throat specialists.
Ear trumpet:A device with a large opening at one end designed to gather sound waves and direct them through a smaller opening into the outer ear canal.
Ear wax: in the external ear canal. Syn: cerumen
Eustachian tube:: Tube about 1 1/2 inches (36 mm) long an 1/8" to 1/4" (3 mm to 6 mm) in diameter, leading from the nasopharynx to the middle ear. Normally makes possible equalisation of pressure between the middle-ear and outside air. Syn: auditory tube (tuba auditiva).
External auditory canal: : The passage from the pinna to the eardrum through which sound waves travel.
e2e Wireless™: Technology for coupling and synchronization of two hearing instruments into one holistic, binaural hearing system.
ePocket™: Remote control unit for CENTRA, ACURIS, ACURIS Life, and ARTIS e2e hearing instruments with read out function for, volume control setting, program and battery status.
Feedback: : A whistling or tone created by sound escaping the ear canal and then re-amplified by the hearing instrument.
Feedback Cancellation System: A circuit or algorithm that detects and eliminates feedback in a hearing instrument.
FM System: A listening device that improves listening in noise. Signals are transmitted from a talker to the listener by FM (frequency modulation) radio waves. The system uses a transmitter and a receiver. To connect the FM system with the hearing instrument, an audio shoe is necessary.
Frequency: Frequency is defined as the number of oscillations per second and is identified by the unit Hertz. The most important frequencies for speech intelligibility are between 100 and 3000 Hz. In hearing instrument technology, frequencies above 3000 Hz are considered to be highThe gain of a hearing instrument based on frequency is displayed graphically. The resulting curve is called the frequency response curve.
Fully-Digital Hearing Instruments: Hearing instruments that convert the analog signal received at the microphone into a digital signal. The digital signal is processed corresponding to the commands of the programmed software (algorithm) and the integrated circuits on the chip. When processing is complete, the digital signal is converted back into analog signals, amplified, and sent to the hearer. Digitization allows for analysis and filtering of signals with respect to speech and noise. The incoming signal is measured at specific time intervals (signal sampling). The more frequent the signal sampling, the better the reproduction of the input signal. The key advantage to this complex signal processing is the more precise compensation for hearing loss, in particular when providing optimum speech intelligibility in a noisy environment.
Genetic deafness: Deafness transmitted by faulty genes.
Hair cell: (1.) One of the specific sensory cells of the organ of hearing (organ of Corti). One end has hair like projections (cilia) that are imbedded in or in contact with the tectorial membrane. The other end is in close contact with many nerve endings. There are about 400 hair cells per millimeter and about 80 cilia per cell. (2.) One of the specific sensory cells of the organ of balance within the vestibule and semicircular canals of the inner ear.
Hearing: One of the five senses - the one that responds to sound pressure waves.
Hearing aid: An electronic amplifying device to make sounds audible to the individual with a hearing loss. Sound pressure waves are converted into electricity by a microphone. The electric impulses are then amplified through controlled electronic circuitry. The amplified electric impulses are then reconverted by a receiver to pressure waves at a much more intense level to be presented to the impaired ear. Syn: hearing instrument.
Hearing Impairment: A hearing problem can have many different causes. Hearing ability is reduced when one or more elements from the outer ear to the brain are affected (see Conductive Hearing Loss and Sensorineural Hearing Loss).
Hearing Program: With the development of digitally programmable hearing instruments, it became possible to provide patients with a 2nd hearing program in addition to the basic instrument settings. For example, while the first hearing program is used for "speech in quiet" situations, the 2nd hearing program is used primarily for "speech in noise" situations. The patient can select which hearing program to use with the touch of a button. Current modern hearing instruments from Siemens have up to four different hearing programs that can be adapted individually to the user's requirements.
Hearing Threshold: The cut-off point between being able to hear and not being able to hear. In other words, the intensity level of sound at which an average adult listener will just be able to hear a sound. For adults is given as a reference level of 0 dB. The hearing threshold for newborns does not apply because their threshold develops to a normal level at around three to five years of age. Generally, newborns begin to hear at levels higher than 0 dB.
Helmholtz' resonance theory: (From Hermann von Helmholtz, German physician and physicist, 1821-1894). The theory that, the hair cells within the organ of Corti act as resonators, each with its own natural period of vibration and responding only to one tone of one particular frequency.
Hertz, Hz (hertz): The term used for cycles per second - named in honour of the German physicist, Heinrich Hertz, 1857-1894.
High fidelity: The reproduction or amplification of sound waves with a minimum of distortion.
High frequency: An inexact term which, in audiology, generally refers to any frequency above 1000 Hz.
Hydrophobic: Afraid of or hostile towards water; hydrophobic materials can hardly or not at all be dissolved by water. A hydrophobic surface is water repellent.
Hysterical deafness: Non organic or functional hearing loss sometimes unconsciously developed as a psychic protection under conditions of severe emotional strain. Syn: conversion deafness.
Impression: A cast made of the contours within the external ear from which an earmold (for BTE instruments) or custom shell (for ITE, ITC and CIC instruments) is made. Impressions typically are made using a silicone material which is plastic for insertion and cures within a few minutes for removal.
In-the-ear (ITE) and In-the-canal (ITC) aids: : Are custom-designed to fit the wearer's ear. Inconspicuous once in place, they fit comfortably and securely inside the ear or ear canal, to most closely imitate the natural hearing process. These one-piece models have no cords or wires. Nearly 80 percent of all aids recommended today in North America are either ITC, CIC or ITE models.
Inner ear: Portion of the ear bounded externally by the oval and round windows and internally by the internal auditory canal. It contains the cochlea and semicircular canals.
Inner Ear Hearing Loss: See Sensorineural Hearing Loss.
Internal auditory canal: : An opening in the petrous portion of the temporal bone through which the auditory and facial nerves and blood vessels pass.
Invasive Procedure: : Usually means a surgical procedure.
Jumper: One who jumps at a loud sound as the result of a nervous disorder.
Just noticeable difference (jnd) also known as difference limen (DL) or differential threshold:The smallest change in frequency or intensity that can be recognised. As the smallest recognisable change in intensity, it approximates the decibel.
KEMAR:Knowles Electronic Manikin for Acoustical Research. "Kemar" is a standardized mannequin used worldwide for auditory testing, especially those tests where the body or head plays a role, e.g., when measuring hearing instruments containing a directional microphone.
Keratosis obturans: A hard plug of wax and dry skin sometimes found in the external and auditory canal.
Kinesthetic cues: : Bodily sensations that aid a deaf person in controlling speech, e.g., jaw and lip positions and nasal vibrations.
Kymograph: A device that makes a record of sound vibrations by means of a stylus activated by a tuning fork as a rotating cylinder passes beneath it.
LASR (Laser Accurate Shell Replication): A Manufacturing technology for ITE instruments which allows ensures exact modeling of the earmold impression.
Lip read: To understand by close observation of the speaker's lips. It is now more commonly known as speech reading, since facial expression and gestures enter into communication. Syn: lip reading.
Localization: Finding the azimuth (location in space) of a sound source by comparing time and intensity differences between the ears.
Loudness: Loudness indicates the subjective perception of volume provoked by a signal. Physically identical sound levels can result in very different perceptions of loudness. The perception of loudness among people with normal hearing is calculated from the signal characteristics. During hearing instrument fitting, loudness is measured using a loudness scaling in categories.
Loudness level (LL) : The loudness level of a sound is determined by comparison for equal loudness with a 1000 Hz tone re .0002 dyne c/m2 when heard binaurally in sound field. The unit of loudness level is known as the "phon." It is numerically equal to the SPL of the 1000 Hz tone, but varies with frequency.
Loudness Recruitment :: In the case of loudness recruitment, the hearing impaired person first begins to hear at higher sound pressure levels; however, said person "catches up" in terms of sensitivity to loudness. This means the hearing-impaired person can have the same sensitivity to loud noises as a person with normal hearing.
Low frequency :An inexact term that is generally refers to a frequency of 1000 Hz and below.
Malleus :pl. mallei. Also called the hammer, the malleus is the first and largest of the ossicles. The handle is attached to the eardrum, while the head is attached to the roof of the tympanic cavity by the superior malleolar ligament, and moves (articulates) with the incus (anvil). It is about 8 mm long.
Masking noise :(1). A mixture of frequencies made up in various ranges - narrow, broad, white, or complex - introduced into one ear to prevent the hearing by that ear of a tone or sound presented to the other ear. (2). Any unwanted sound that interferes with the ability to hear the wanted sound.
Mastoid : Raised portion of the temporal bone behind the external ear: the mastoid process.
Mastoiditis :Inflammation within the air cells of the mastoid.
Menier's disease :Meniere's syndrome (Prosper Meniere, French physician, 1799-1862). Endolymphatic hydrops - the malfunction of hearing and balance caused by excessive inner ear fluids. A condition whose intermittent symptoms include dizziness, nausea, tinnitus, and progressive deafness. Syn: labyrinthine hydrops.
Microphone sound-probe :Tiny microphone on a thin rod or cylinder designed to study sound waves in small confined spaces such as the ear canal with a minimum of disturbance to the wave form. Also known as a probe-mic system.
Middle ear :Syn: Auris media, or tympanic cavity. The portion of the hearing mechanism between the outer and inner ears. Consists of the eardrum, the ossicles, the opening of the eustachian tube, the oval window, and the round window.
Mixed hearing loss :One which contains elements of both conductive and sensorineural hearing loss.
Modulation / Modulation Frequency : If one looks at the temporal display of a voice signal, one will note a temporal structure (modulation) in the envelope curve. The structure is formed by the temporal sequence of words, syllables, and phonemes. The speed at which the loud and soft portions follow in sequence is called modulation frequency. Language generally has a modulation frequency between 3 and 6 Hz.
Multichannel adaptive microphone : A directional microphone system that is controlled by a digital signal processing algorithm that allows the processing of the signal in several frequency regions. Each frequency region can recognize a different noise source/masker. This allows the system to reduce the effects of up to four different noise maskers, provided they are separated in frequency.
Narrow-band Noise :A sound stimulus generally produced by one-third octave band filtering of broad-band white noise.
Notch :A negative reduction in a frequency response.
Occlusion : The perception of increased loudness of a bone-conducted signal when the outer ear is somehow blocked (covered by earphone or earmold).
Oleophobic :: Afraid of or hostile towards oil or grease; oil and grease do not adhere to oleophobic surfaces. They can easily be wiped off.
Omnidirectional :A term from directional microphone technology indicating the mode of operation of microphones that receive sounds with the same sensitivity in all directions. If one turns a microphone 360° in front of a sound source and draws a diagram of the voltage produced by the microphone, the result is the spherical characteristic. These microphones are also called omnidirectional.
Omnidirectional microphone : A term used to describe a microphone that records in all direction. This is also referred to as a spherical microphone. See the term Omnidirectional.
Organ of Corti : A structure resting on the basilar membrane within the cochlear duct (scala media). It contains the essential sensory elements of hearing, the hair cells, and their supporting cells. The function of the hair cells is to convert sound pressure waves into nerve impulses, which are transmitted by way of the eighth cranial nerve to the brain. It is the end-organ of hearing. Syn: organum spirale.
Ossicles auditory : The small bones of the middle ear that convey sound impulses from the eardrum to the oval window. They are known as the hammer (malleus), anvil (incus), and stirrup (stapes).
Otitis :A broad term for inflammation of the ear.
Otoplastic :: Ear mold created by the audiologist based on a three-dimensional ear impression of the auditory canal, the Concha, and a clip, up to the Triangular Depression. It is used to secure and provide soundproofing for the hearing instrument. Sound from the hearing instrument is sent through the auditory canal to the area before the eardrum. Soundproofing is important to prevent feedback whistling.
Otosis : pl. otoses. (1). Mishearing or misunderstanding of spoken sounds. (2). Mispronunciation of words resulting from faulty hearing.
Perforated eardrum :An eardrum that has been ruptured by accident or disease. The reduction in hearing sensitivity usually amounts to about 5 or 10 dB.
Phoneme :(1).One of the smallest units of speech (or class of phones) that distinguishes one word from another: e.g., p, b, and f in pan, ban, and fan. (2). Hearing of imaginary voices.
Pinna :The portion of the ear that is visible on the side of the head. Adj. pinnal; Syn: auricle.
Pitch absolute :The ability to identify unerringly the fundamental frequency of a tone that is heard.
Play Audiometry (CPA) :A hearing test where an audiologist teaches a child to respond when a sound is heard by playing some sort of game. For example, the child puts a block in a box every time a sound is heard.
ower-on-Delay : The hearing system is automatically turned on with a delay of 12 seconds, so that you may insert the hearing instrument into your ear without experiencing unpleasant feedback (whistling).
Profound deafness : Extreme hearing impairment bordering on total deafness. A degree of loss so severe that hearing aid amplification must be supplemented by speech reading at all times to be effective. Numerically, it is generally considered to be an average of over 90 dB at 500, 1000, and 2000 Hz audiometrically (ANSI).
Pure tone : A continuous sinusoid of a single frequency. Commonly used in basic hearing screening tests.
Quinine : A drug formerly used for the prevention of malaria. Now a part of many cold remedies and abortifacients, it may cause deafness in susceptible individuals.
Range of comfortable loudness (RCL) :A range of sound pressure intensities that are subjectively comfortably loud for the individual.
Real Ear Aided Response (REAR) :): The sound pressure level, as a function of frequency, at a specified point in the ear canal for a specified sound field, with a hearing aid in place and turned on. Primarily a measurement of the hearing aid's response, and used as a reference for insertion gain calculations. (REAR-REUR=REIG).
Real-ear attenuation : A measurement of the amount by which ear protectors lessen sound pressure reaching the eardrum of a particular observer. It is expressed in decibels of difference between thresholds of audibility when the ears are open and when they are protected.
Real Ear Insertion Response (REIR) :The difference, in decibels as a function of frequency, between the REUR and the REAR measurements taken at the same measurement point in the same sound field. The Real Ear Insertion Gain (REIG) is the value, in decibels, of the REIR at a specific frequency. REIR is the amount of gain delivered to a patient wearing a hearing aid that they did not have before the hearing aid fitting.
Real-ear gain : Real-ear gain: The additional sound pressure reaching the eardrum when a hearing aid is used - compared to the sound pressure reaching the eardrum without a hearing aid. Syn: etymotic, orthotelephonic, or insertion gain (REIG).
Real Ear Occluded Response (REOR) : The sound pressure level, as a function of frequency, at a specified point in the ear canal for a specified sound field, with a hearing aid in place and turned off. Primarily a measurement of the effect of the placement of the hearing aid or earmold in the ear.
Real Ear Unaided Response (REUR) :The sound pressure level, as a function of frequency, at a specified point in the unoccluded ear canal for a specified sound field. Primarily a measurement of the resonance characteristics of the ear canal and the concha.
Receiver : A device that converts (transduces) electrical impulses into sound waves (or signals). Syn: earphone, speaker, transducer.
Remote Control Unit : A device that can be used to control specific features of a hearing instrument system such as volume and program change. It may also provide read-out functions of the hearing instruments such as battery status.
Resonance Frequency :The frequency at which something vibrates naturally when stimulated. When struck, for example, a tuning fork will resonate at a specific frequency.
Sensorineural hearing loss :Hearing loss (also known as nerve deafness), one in which the bones, eardrum and membranes are intact, but a deterioration of the inner ear is present. This may be caused by the natural aging process, or degeneration of the nerves leading from the inner ear to the brain.
Severe deafness :A hearing loss between 70 dB and 90 dB when the hearing threshold level at 500, 1000 and 2000 Hz in the better ear is averaged.
Short increment sensitive index (SISI) :A test of the ability to recognise one decibel increases in intensity during a series of bursts of pure tone presented 20 dB above threshold.
Sign language : A system of conventional symbols or gestures made with the hands to help the deaf communicate. It is distinct from finger spelling. There are various systems, among them American Sign Language, ASL (AMESLAN); Linguistics of Visual English, LOVE or LVE; Seeing Essential English, SEE1; Signed English, SE (Siglish); Signing Exact English, SEE2; Systematic Sign Language, SLL. Signed English SE (Siglish): A modification of American Sign Language (AMESLAN) developed by Harry Bornstein and associates at Gallaudet College. It is designed to present a formalized gesture system that will help children learn to communicate more easily with better syntax and grammar.
Situation Detection : The process of detecting the incoming signal to a hearing instrument and classifying it against known signal patterns to determine the optimal processing necessary for that listening environment.
Ski slope Hearing Loss : Audiogram that is characterized by progressively increasing high frequency hearing loss.
Speech & Noise management :Digital technology makes Speech & Noise management technology possible by using special listening programs, (algorithms) to offer personalized sound processing for specific listening needs such as listening to music. This technology automatically helps minimize or reduce background noise in many hearing situations.
Spiral cochlear canal : Commonly known as the spiral canal of the cochlea. A portion of the bony labyrinth of the inner ear about 30 mm long making 2 3/4 turns about a central bony supporting structure known as the modiolus. It contains the scala tympani, scala vestibuli and cochlear duct. Syn: Rosenthal's canal.
Sound :(1).The sensation resulting from stimulation of the auditory mechanism by air waves or vibrations. (2).An instrument that may be inserted into a cavity or tube (e.g., eustachian) for diagnosis or treatment.
Stapes :pl. stapes, stampedes. Also known as the stirrup, the stapes is the third and inner bone of the ossicular chain. Moved by the incus, the stapes vibrates in the oval window.
Synchronization :Events occurring at the same time. The process of a binaural hearing system using information from each ear to arrive at a common (synchronized) set of signal processing parameters.
Telecoil :In a hearing situation, the hearing instrument picks up sounds with the microphone. For this reason, most hearing instruments have an induction coil (telecoil) built in. It receives the inductive field emission the telephone receiver and transmits it to the amplifier. To activate the telecoil, the instrument must be set to telecoil mode using a switch (0-T-M). An induction coil may also be used to receive signals from an induction loop, such as those found in churches, schools, or lecture halls, resulting in improved transmission without ambient noise.
TILL Treble Increase at Low Levels : A type of compression amplification system which attenuates (reduces) the amount of high frequency gain as input signal levels increase.
Tinnitus : Noises seeming to originate within the ear itself. Syn: susurrus aurium, tinnitus cerebri, tinnitus aurium.
Tone deafness :Inability to recognize musical tones or pitch differences. In extreme cases it is known as amusia.
Treble :The highest voice part in harmonic music.
Tympanic membrane : Also called the eardrum, drum membrane and drumhead. It stretches across the inner end of the external ear canal and forms the outer boundary of the middle ear. It reacts to sound waves and starts the ossicular chain moving. It is about 1/3 inch (7 or 8 mm) in diameter.
Ultrasonic sound : Sound pressure waves whose frequency is above the audible range. Sometimes called ultra-audible sound.
Uncomfortable loudness or uncomfortable loudness level (UCL or ULL) :The intensity level at which a tone or sound subjectively becomes uncomfortably loud.
Utricle :The larger of the two sacs that occupy a portion of the membranous labyrinth of the vestibule of the inner ear. (The smaller sac is the saccule).
Utriculitis :(1.) Inflammation involving the utricle of the vestibule. (2.) Inflammation of the inner ear.
Vertigo Dizziness :or a sensation of whirling or irrigular motion that arises from problems within the vestibular portion of the inner ear. Objective vertigo is the name given the sensation that the world is spinning about the patient. Subjective vertigo indicates the patient feels he is moving in space. Adj: vertiginous.
Vestibule :Portion of inner ear between cochlear and semicircular canals. It contains the saccule and the utricle.
Volume : Used interchangeably for either intensity or loudness.
Warble tone :A tone resulting from rapid modulations of frequency within fixed limits around the basic pure tone frequency. Commonly used in real ear measurements as they are not easily influenced by standing waves from reflective surfaces.
Wave sound :A change in the arrangement of molecules in a medium into successive patterns of compression and rarefaction.
Whisper test :An obsolete and inadequate method of testing hearing.
Xanthomatosis : A metabolic disorder marked by deposits of yellow or orange nodules in the skin. It is sometimes associated with tinnitus.
Y-cord : A hearing aid cord that divides the electrical impulse from one transmitter to two receivers. A modified form is known as a V-cord. Syn: pseudobinaural.
Zone of normal hearing :The range of thresholds for speech from 0 to 25 dB (ISO).