Standardized audiological test results not only improve the diagnostic level of clinical disease, but also help guide treatment intervention and assessment results. Hearing is a very subtle feeling of the human body. A slight decrease in hearing may make your quality of life greatly compromised. When hearing loss occurs, the necessary hearing tests should be performed in a timely manner. So, what are the common hearing test items?
First, pure tone audiometry
The most basic type of hearing test is “pure tone audiometry”, which tests the entire auditory conduction path from the sound wave collected by the auricle to the beginning, and the sound wave is transformed into a nerve impulse to the auditory center of the brain. You can understand the normality of hearing and the extent and nature of hearing loss, and as a basis for diagnosis and treatment.
Pure tone audiometry uses a single frequency of sound through the air conduction and bone conduction headphones to give the sound, by judging the minimum sound heard at each frequency, understanding the hearing loss of each frequency to draw an audiogram, according to the audiogram to understand the extent and nature of deafness. The air conduction test frequency range is125Hz~8k HZ, bone conduction test frequency range250~4K HZ.
According to the test gas bone conduction spacing can be divided into4Type:1Normal: The gas bone conduction is in the normal range.2Conductive sputum: air conduction decreases bone conduction is normal.3Sensorineural deafness: the air-bone conduction is decreased but the air-bone conduction is in10dBWithin.4Mixed deafness: air conduction bone conduction decreases at the same time, gas bone conduction difference is greater than10dB.
Second, the acoustic impedance
The “acoustic impedance” test is an objective test method for observing the functional state of the auditory system by the biophysical changes of the middle ear transmission structure caused by acoustic stimulation. The purpose is to detect the middle ear condition.
The acoustic impedance test mainly includes tympanometry test, acoustic reflection threshold and acoustic reflection attenuation. Tympanometry test:AType: normal type;AsType: common sacral sclerosis;AdType: common in the tympanic membrane relaxation;BType: common in middle ear effusion, secretory otitis media;CType: Common in eustachian tube dysfunction.
Third, the otoacoustic emission
Otoacoustic emissions are generated in the cochlea, and are transmitted to the external auditory canal through the ossicular chain and the tympanic membrane. It reflects that the cochlea not only passively feels the sound signal, but also has the function of actively generating audio energy. This test can reflect the functional status of the outer hair cells of the cochlea.
Induced by the presence of external stimulus signals, it is divided into spontaneous otoacoustic emissions and induced otoacoustic emissions. Among them, the induced otoacoustic emission is divided into transient acoustic evoked otoacoustic emission according to the difference of its stimulating sound (TEOAEDistortion product otoacoustic emission (DPOAE), stimulating frequency otoacoustic emissions (SFOAE), electrically induced otoacoustic emissions (EEOAE).
Commonly used clinicallyDPOAE/TEOAEPerform hearing tests.DPOAESignal to noise ratio>=3-6dB.DPvalue>= -10dBRegarded as passing;TEOAE 一
般以各频段信噪比>=3-6dBTotal correlation coefficient> 70%, deemed to pass.
Fourth, speech measurement
Speech audiometry refers to an audiological test method that uses a speech signal as an acoustic stimulus to examine a subject’s speech threshold and verbal recognition ability. In daily life and work,The ability to understand speech is the most important indicator for judging the state of the listening function. Check if the subject can understand the speech,It is an important project for evaluating human hearing function.
The most commonly used test items in speech audiometry: speech recognition rate, speech recognition threshold.
Speech recognition rate: For a subject, the specified speech level and the specified transmission method can correctly identify the percentage of the actual examination item at the specified speech level;
Speech recognition threshold: For a subject, just understand the sent speech signal50%The intensity of the sound.
V. Behavioral listening
Behavioral audiometry: An audiological test method that specifically evaluates children. Including behavioral observations (less than6Infants and young children); visual enhancement (7Month to3Older children); game audiometry (3-6
The main point of the operation of behavioral audiometry is to choose the method of listening and listening to the child. You can’t just look at the real age of the child. It is necessary to choose according to the age of the mind. It is very important to adapt to the situation. If the child is four and a half years old, the game should be selected for normal listening and listening; but if his intelligence, communication ability, etc. are only two years old, it may not match the game audiometry, you can choose visual enhanced audiometry or both. Combined testing. Similarly, if the child is seven years old, but the pure tone is not matched, you can choose the game to listen to.
Sixth, auditory brainstem response test
Auditory brainstem responseABR): refers to the auditory system to hear the stimulation of the sound stimulation and accompanying the potential changes, can be located in the diagnosis of lesions from the auditory nerve to the brainstem auditory pathway, is of great significance in the diagnosis of post-cochlear lesions.
It originates from the various nuclei of the auditory nerve and brain stem, and receives stimulation.10msGenerated internally5~7Waves, of whichI,III,VThe wave is the most obvious,VThe wave diagnostic hearing threshold is the most important. Short-sound brainstem response threshold2~4kHzIt is closest to the listening threshold of pure tone behavior.
Under normal circumstancesV波5.5~5.7msAppear, two earsVWave latency difference is not greater than0.40ms.I–VWave interval is not greater than4.6ms. Sensorineural deafnessABRThe absolute latency is extended. Also emphasizeABRListening and listening to short sounds only respond to high frequency hearing, nervous system diseasesABRThe result can be abnormal.
Sixth, auditory steady state response test
Auditory steady state responseASSR): It is an auditory evoked potential that is induced by a modulated acoustic signal and reflects a stable relationship between the phase and the phase of the stimulus signal.ABR. test500,1000,2000,4000HZ 4Frequency, with frequency specificity. Hearing conditions at different frequencies for newborn babies, young children, or people who are unable to work with behavioral tests can be assessed.
Link：How much is the hearing test?REF: Hearing aids China, Hearing Aids Supplier , Hearing Aids Types
The article comes from the Internet. If there is any infringement, please contact [email protected] to delete it.