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Weber Test
The Weber test is a screening test for hearing performed with a tuning fork. It can detect Unilateral hearing loss, unilateral (one-sided) conductive hearing loss (middle ear hearing loss) and unilateral sensorineural hearing loss (inner ear hearing loss). The test is named after Ernst Heinrich Weber (1795–1878). Conductive hearing ability is mediated by the middle ear composed of the ossicles: the malleus, the incus, and the stapes. Sensorineural hearing ability is mediated by the inner ear composed of the cochlea with its internal basilar membrane and attached cochlear nerve (cranial nerve VIII). The outer ear consisting of the pinna, ear canal, and ear drum or tympanic membrane transmits sounds to the middle ear but does not contribute to the conduction or sensorineural hearing ability save for hearing transmissions limited by cerumen impaction (wax collection in the ear canal). The Weber test has had its value as a screening test questioned in the literature. Weber tes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuning Fork
A tuning fork is an acoustic resonator in the form of a two-pronged fork with the prongs ( ''tines'') formed from a U-shaped bar of elastic metal (usually steel). It resonates at a specific constant pitch when set vibrating by striking it against a surface or with an object, and emits a pure musical tone once the high overtones fade out. A tuning fork's pitch depends on the length and mass of the two prongs. They are traditional sources of standard pitch for tuning musical instruments. The tuning fork was invented in 1711 by British musician John Shore, sergeant trumpeter and lutenist to the royal court. Description A tuning fork is a fork-shaped acoustic resonator used in many applications to produce a fixed tone. The main reason for using the fork shape is that, unlike many other types of resonators, it produces a very pure tone, with most of the vibrational energy at the fundamental frequency. The reason for this is that the frequency of the first overtone is about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ear Procedures
In vertebrates, an ear is the organ that enables hearing and (in mammals) body balance using the vestibular system. In humans, the ear is described as having three parts: the outer ear, the middle ear and the inner ear. The outer ear consists of the auricle and the ear canal. Since the outer ear is the only visible portion of the ear, the word "ear" often refers to the external part (auricle) alone. The middle ear includes the tympanic cavity and the three ossicles. The inner ear sits in the bony labyrinth, and contains structures which are key to several senses: the semicircular canals, which enable balance and eye tracking when moving; the utricle and saccule, which enable balance when stationary; and the cochlea, which enables hearing. The ear canal is cleaned via earwax, which naturally migrates to the auricle. The ear develops from the first pharyngeal pouch and six small swellings that develop in the early embryo called otic placodes, which are derived from the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audiometry
Audiometry () is a branch of audiology and the science of measuring hearing acuity for variations in sound intensity and pitch and for tonal purity, involving thresholds and differing frequencies. Typically, audiometric tests determine a subject's hearing levels with the help of an audiometer, but may also measure ability to discriminate between different sound intensities, recognize pitch, or distinguish speech from background noise. Acoustic reflex and otoacoustic emissions may also be measured. Results of audiometric tests are used to diagnose hearing loss or diseases of the ear, and often make use of an audiogram. History The basic requirements of the field were to be able to produce a repeating sound, some way to attenuate the amplitude, a way to transmit the sound to the subject, and a means to record and interpret the subject's responses to the test. Mechanical "acuity meters" and tuning forks For many years there was desultory use of various devices capable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Presbycusis
Presbycusis (also spelled presbyacusis, from Greek πρέσβυς ''presbys'' "old" + ἄκουσις ''akousis'' "hearing"), or age-related hearing loss, is the cumulative effect of aging on hearing. It is a progressive and irreversible bilateral symmetrical age-related sensorineural hearing loss resulting from degeneration of the cochlea or associated structures of the inner ear or auditory nerves. The hearing loss is most marked at higher frequencies. Hearing loss that accumulates with age but is caused by factors other than normal aging ( nosocusis and sociocusis) is not presbycusis, although differentiating the individual effects of distinct causes of hearing loss can be difficult. The cause of presbycusis is a combination of genetics, cumulative environmental exposures and pathophysiological changes related to aging. At present there are no preventive measures known; treatment is by hearing aid or surgical implant. Presbycusis is the most common cause of hearing loss, affec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bing Test
Bing most often refers to: * Bing Crosby (1903–1977), American singer * Microsoft Bing, a web search engine Bing may also refer to: Food and drink * Bing (bread), a Chinese flatbread * Bing (soft drink), a UK brand * Bing cherry, a variety of cherry * Twin Bing or Bing, a candy made by Palmer Candy Company Names * Bing (German surname), a German-language surname * Bing (Chinese surname) (邴), a Chinese surname Places * Bing Prefecture, an ancient Chinese province * Bing, Hormozgan, a village in Hormozgan Province, Iran * Binag, Sistan and Baluchestan, a village in Sistan and Baluchestan Province, Iran * Manor of Byng, Suffolk, England Television * ''Bing'' (TV series), a British children's television series * Bada Bing or the Bing, a fictional strip club in ''The Sopranos'' * Bing or Evan Chambers, a character in ''Greek'' Other uses * Bing (company), a German company that manufactured toys and kitchen utensils * Bing (dog), a British dog who served in Worl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occlusion Effect
The occlusion effect occurs when an object fills the outer portion of a person's ear canal, causing that person to perceive echo-like "hollow" or "booming" sounds generated from their voice, chewing, footsteps, or any other sounds originating in their own body. The bone-conducted sound travels to the cochlea through different pathways. The outer ear pathway corresponds to the sound pressure generated in the ear canal cavity due to the vibration of the ear canal wall, which constitutes the source of the occlusion effect. At low frequencies, the outer ear pathway is negligible when the ear canal is open but dominates when the ear canal is occluded. The occlusion effect is thus objectively characterized by an acoustic pressure increase in the occluded ear canal at low frequencies and which can be measured with a probe-tube microphone. Considering that the vibrating ear canal wall acts as an ideal source of volume velocity (also known as volumetric flow rate), the occlusion device inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Ear
The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts: * The cochlea, dedicated to hearing; converting sound pressure patterns from the outer ear into electrochemical impulses which are passed on to the brain via the auditory nerve. * The vestibular system, dedicated to balance (ability), balance. The inner ear is found in all vertebrates, with substantial variations in form and function. The inner ear is innervated by the eighth cranial nerve in all vertebrates. Structure The labyrinth can be divided by layer or by region. Bony and membranous labyrinths The bony labyrinth, or osseous labyrinth, is the network of passages with bony walls lined with periosteum. The three major parts of the bony labyrin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rinne Test
The Rinne test ( ) is used primarily to evaluate loss of hearing in one ear. It compares perception of sounds transmitted by air conduction to those transmitted by bone conduction through the mastoid. Thus, one can quickly screen for the presence of conductive hearing loss. A Rinne test should always be accompanied by a Weber test to also detect sensorineural hearing loss and thus confirm the nature of hearing loss. The Rinne test was named after German otologist Heinrich Adolf Rinne (1819–1868); the Weber test was named after Ernst Heinrich Weber (1795–1878). Procedure The Rinne test is performed by placing a 512 Hz vibrating tuning fork against the patient's mastoid bone and asking the patient to tell you when the sound is no longer heard. Once the patient signals they can't hear it, the still vibrating tuning fork is then placed 1–2 cm from the auditory canal. The patient is then asked again to indicate when they are no longer able to hear the tuning fork. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test For Hearing
A hearing test provides an evaluation of the sensitivity of a person's sense of hearing and is most often performed by an audiologist using an audiometer. An audiometer is used to determine a person's hearing sensitivity at different frequencies. There are other hearing tests as well, e.g., Weber test and Rinne test. Ear examination Prior to the hearing test, the ears of the patient are usually examined with an otoscope to make sure they are free of wax, that the eardrum is intact, the ears are not infected, and the middle ear is free of fluid (indicating middle ear infection). Pure tone audiometry The standard and most common type of hearing test is pure tone audiometry, which measures the air and bone conduction thresholds for each ear in a set of 8 standard frequencies from 250Hz to 8000Hz. The test is conducted in a sound booth using either a pair of foam inserts or supraural headphones connected to an external audiometer. The result of the test is an audiogram diagram whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stapes
The ''stapes'' or stirrup is a bone in the middle ear of humans and other tetrapods which is involved in the conduction of sound vibrations to the inner ear. This bone is connected to the oval window by its annular ligament, which allows the footplate (or base) to transmit sound energy through the oval window into the inner ear. The ''stapes'' is the smallest and lightest bone in the human body, and is so-called because of its resemblance to a stirrup (). Structure The ''stapes'' is the third bone of the three ossicles in the middle ear and the smallest in the human body. It measures roughly , greater along the head-base span. It rests on the oval window, to which it is connected by an annular ligament and articulates with the ''incus'', or anvil through the incudostapedial joint. They are connected by anterior and posterior limbs (). Development The ''stapes'' develops from the second pharyngeal arch during the sixth to eighth week of embryological life. The central ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incus
The ''incus'' (: incudes) or anvil in the ear is one of three small bones (ossicles) in the middle ear. The incus receives vibrations from the malleus, to which it is connected laterally, and transmits these to the stapes medially. The incus is named for its resemblance to an anvil (). Structure The incus is the second of three ossicles, very small bones in the middle ear which act to transmit sound. It is shaped like an anvil, and has a long and short crus extending from the body, which articulates with the malleus. The short crus attaches to the posterior ligament of the incus. The long crus articulates with the stapes at the lenticular process. The superior ligament of the incus attaches at the body of the incus to the roof of the tympanic cavity. The incus is Homology (biology), homologous to the quadrate bone found in other tetrapods. Function Vibrations in the middle ear are received via the tympanic membrane. The malleus, resting on the membrane, conveys vibrations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
